Mooban planning
Contents

Model results (generated)

Generated by python model/cost_model.py. Do not edit by hand; change the assumptions in the script (or model/estate_energy.py) and re-run. All figures THB, estimates, 2026 prices. Premium rents are all-inclusive (docs/operating-model.md).

Estates

Estate Land Houses Land cost Infrastructure Infra per house Central battery PV per house
Flagship: 16.9 rai, 14 houses round a natural park, Hang Dong / Nong Khwai area 16.9088 rai @ 4.80 M/rai 8xA, 2xB, 4xC 81.16 M 70.69 M 5,049,643 170 kWh 6 kWp (roof ready for 10)
Lean: 6.5 rai, 12 houses round a park, outer Hang Dong / Saraphi 6.5 rai @ 2.50 M/rai 12xA 16.25 M 34.53 M 2,877,917 130 kWh 6 kWp (roof ready for 10)
Pilot: 2 houses on a 0.6 rai serviced plot, Hang Dong 0.6 rai @ 6.00 M/rai 2xA 3.60 M 2.65 M 1,325,000 30 kWh 6 kWp (roof ready for 10)

All-in cost per house

Line flagship A premium flagship B premium lean A premium lean A standard pilot A premium flagship C premium
Land incl. share of roads/common (m2) 1,784 1,862 867 867 480 2,265
Land 5,512,119 5,753,139 1,394,792 1,394,792 1,854,000 6,998,409
Estate infrastructure share (incl. shared grid, battery, water plant) 5,049,643 5,049,643 2,877,917 1,787,667 1,325,000 5,049,643
Base build (TAF medium x GFA) 2,502,000 3,336,000 2,502,000 2,502,000 2,502,000 4,170,000
Spec upgrades (see breakdown) 2,897,400 3,472,000 2,897,400 131,000 2,897,400 5,200,600
Attached garage, 2 cars (Type C: 3) (see breakdown) 521,000 521,000 521,000 342,500 521,000 763,000
Plot works (driveway, paths, fence, garden) 195,000 245,000 195,000 95,000 195,000 380,000
Appliances, wardrobes, blinds 330,000 410,000 330,000 200,000 330,000 520,000
Soft costs 1,034,554 1,173,028 839,098 303,490 699,336 1,447,492
Contingency 1,252,960 1,420,667 1,016,242 375,316 846,974 1,753,073
Finance during build 578,840 641,414 377,203 213,953 335,121 788,467
Total all-in 19,873,515 22,021,891 12,950,652 7,345,717 11,505,831 27,070,683
House only (base + upgrades) per m2 GFA 29,997 28,367 29,997 14,628 29,997 31,235
House without land, per m2 GFA 79,786 67,786 64,199 33,061 53,621 66,908

Spec upgrade breakdown, Type A (2,897,400 THB)

Item THB Basis
Structure: raised plinth (flood), termite barrier, seismic detailing 150,000 est.
Walls: 75-100 mm external insulation (ETICS / mineral wool) on AAC, delta 320,000 est. 1,600 THB/m2 wall
Roof: 150 mm insulation, ventilated metal roof, cool coating, sarking, delta 243,000 est. 1,800 THB/m2 roof; spray PU alone is 250-500 THB/m2 [15]
Windows: thermally broken, double glazed Low-E laminated, multipoint locks, delta 399,000 est. 14,000 vs 3,500 THB/m2 installed; Windsor uPVC list ~3,000-9,000 THB/m2 for common sizes + 600 install [14]
Insect screens on every opening 30,400 Windsor vinyl screens ~750 THB/m2 [14]
External doors: insulated, gasketed, multipoint, delta 105,000 est.
External shading: louvres, pergola, deep eaves on W/E 80,000 est.
Airtightness to Passive House level (n50 <= 0.6): membranes, tapes, 3 blower-door tests 80,000 est.; PHI limit 0.6 ACH50 [41]
Passive House certification: PHPP model, certifier, documentation 50,000 est.; one PHPP model per house type and orientation, certificate per house
ERV with F7 + HEPA (H13) filtration, positive pressure, ducting 220,000 est.; ducted clean-air systems 100,000+ THB [17]
Air conditioning: premium inverter (SEER 20+), concealed piping, full cost 160,000 est.; Daikin FTKF 18k BTU installed 26,655 THB [16]
DC ceiling fans in every bedroom and living room 30,000 est.
Heat pump water heater 200-300 L with recirculation, run in solar hours 90,000 est.
Solar PV 6 kWp, string inverter, feeding the estate grid 180,000 est. 30,000 THB/kWp; 10 kW house systems 250,000-430,000 [8]
PV-ready for 10 kWp: rails, penetrations, DC conduit 15,000 est.
Electrical upgrade: tier-1 gear, RCBO per circuit, SPD T1+T2, TN-C-S, conduit, delta 180,000 est.; B4L construction-standards
EV charger 7 kW, metered, controlled by the estate EMS 45,000 est.
Plumbing upgrade: PEX-AL-PEX manifold, silent drainage, check and leak shut-off valves, delta 150,000 est.; B4L construction-standards; no pump, tank or treatment per house
Monitoring: Home Assistant hub, per-room PM2.5/CO2 sensors, energy and water meters, leak sensors 70,000 est.
Life safety: interlinked smoke/heat/CO alarms, extinguishers 15,000 est.
Video intercom: door station, indoor station with SOS button, app; linked to the guard house 35,000 est.; villa door station 12,120 and indoor station 19,410 THB MSRP [52]
Kitchen and bathroom upgrade, delta 250,000 est.

Attached garage (6.5 x 6 m, outside the airtight envelope)

Item Premium Standard twin Basis
Garage shell 6.5 x 6 m: slab, masonry walls, insulated roof ready for PV 351,000 292,500 est. 9,000 THB/m2, between the TAF rates for a car repair garage (4,700-7,400 [60]) and a house (13,900 [1])
Garage door 6 x 2.5 m: sectional, motor, app control, installed 120,000 50,000 105,000 + 3,000 app module, excl. installation [61]
Fire-rated airtight self-closing door to the house, garage ventilation, heat detector, lights, sockets 50,000 est.
Total 521,000 342,500

Estate infrastructure, flagship (70.69 M THB, 14 houses)

Line THB
Land fill (flood margin) and grading 7,300,000
Ring road and two roundabouts, 3,740 m2: kerbs, drainage, landscaped islands with mountable aprons for trucks 8,600,000
Stormwater without open water: underground attenuation tank of about 538 m3 under the west meadow of the park (1 m3 per 50 m2 of site [64], about 6,500 THB/m3 [64]), dry detention meadow that drains within a day [62], controlled outlet to the public drain 3,700,000
Central battery, LFP 170 kWh 2,295,000
Estate grid: 22 kV connection and metering, 250 kVA transformer, main LV board, LV ring of about 316 m to every house, revenue-grade sub-meters 4,200,000
Battery inverter (grid-forming), energy management system, islanding switchgear, fire-rated battery room 1,200,000
Standby generator: 200 kVA diesel in a sound-attenuated canopy with base tank (100-200 kVA sets 0.4-1.2 M THB [68]), installation (10-15 % [68]), changeover and controls with the battery inverter, fenced and bunded compound by the workshop 1,700,000
Water plant: 2 bore wells, treatment (aeration, filtration, UF, UV, chlorine), 60 m3 ground tank, transfer pumps to the tower (duty, standby), pump house 2,300,000
Water tower: 50 m3 steel tank on a 25 m tower (about 540,000 THB [70]) and its foundation (165,000 to 196,000 THB [70]); riser, overflow and drain, level control, lightning protection, caged ladder; gives about 2 bar at the street by gravity [71] 1,000,000
Water ring main of about 316 m, house connections, smart meters, hydrants 1,300,000
Irrigation from treated effluent and a covered rainwater cistern (no open water) 600,000
Central sewage treatment plant 1,800,000
Fibre backbone, network core, common-area Wi-Fi 900,000
Gate access: 3 barrier lanes (2 in, 1 out) with LPR cameras, UHF and card readers, safety radar; pedestrian gate; access and visitor software on a local server 650,000
Video intercom backbone: guard master station, door stations at the gate, pedestrian gate and utility yard, SIP server 200,000
CCTV: gate, perimeter every ~25 m, sports centre; 30-day recorder; perimeter alarm analytics 520,000
Perimeter wall of 658 m with anti-climb top, gate throat and islands, guard house with parcel room 4,300,000
Sports centre, 540 m2: hall with 2 badminton courts, gym, changing rooms, lobby with co-working; hall as a steel building (turnkey halls from about 8,000 THB/m2 [65]), sports floor [66], gym kit 7,700,000
Pool 20 x 8 m with deck, plant room and shade 2,500,000
Padel courts, 2, with lights (Chiang Mai 400,000 to 800,000 THB per court structure [67]), slab and drainage 1,600,000
Padel hall: enclosed steel hall 24 x 22 m over both courts, 9 m high (FIP: at least 6 m clear over the court, 8 m suggested for new halls [69]), insulated roof, closed walls with louvres, ceiling fans (steel halls from about 8,000 THB/m2 [65]) 4,500,000
Multi-use court 28 x 13 m (futsal, basketball): slab, PU hard court [66], fence, lights 950,000
Natural park, 3,509 m2: native meadow and tree groves, gravel loop of about 153 m, natural play, sala (340 THB/m2 plus 400,000 for play and sala, est.) 1,600,000
Places to sit and play in the park: 1 outdoor table tennis table on a pad (60,000 THB each), 1 picnic lawn with two tables (60,000), 1 shade pavilion with benches (300,000), 1 seating circle (150,000), 9 benches along the loop (12,000), 28 flowering shrubs (1,500), 25 park trees (6,000 planted); all est. 870,000
Perimeter trail, 606 m round the estate in the green belt: 2.5 m permeable running surface on a compacted base with edging (about 900 THB/m2, est.), low bollard lights every 25 m (15,000 THB each, est.); green lanes between the plots, 4 lanes, 4 m wide with a 1.5 m path, 104 m (est.); 10 outdoor fitness stations on the trail and in the park (60,000 THB each, est.) 2,510,000
Common landscaping: verges and corner greens (9,020 m2, mostly native meadow at about 150 THB/m2), trees, street lighting 3,500,000
Workshop, spare-parts store, staff room and bin store by the gate 800,000
Permits: building, environmental screening, PEA, groundwater, utility connections 1,600,000

Running costs per house per year (landlord)

Line flagship A premium flagship B premium lean A premium lean A standard pilot A premium flagship C premium
Full service: In-house technical team (share) 77,309 77,309 65,248 77,309
Full service: Consumables (filters, parts, pest control) 15,800 19,750 15,800 15,800 25,280
Full service: Repairs: parts and specialists 12,000 15,000 12,000 12,000 19,200
Full service: Component replacement reserve 97,053 121,316 97,053 97,053 172,785
Estate systems: Water plant: media, membranes, UV lamps, chemicals, lab tests, groundwater fee 6,429 6,429 5,000 6,429
Estate systems: Transfer and well pumps, replacement reserve (360,000 over 12 years) 2,143 2,143 2,143
Estate systems: Water tower: yearly inspection and tank cleaning; repaint reserve (300,000 every 10 years) 3,214 3,214 3,214
Estate systems: Sewage plant: service, sludge removal, blower reserve 6,429 6,429 5,000 6,429
Estate systems: Sports centre, padel hall, pool and courts: AC, fans, sports floor, padel glass and turf, nets, lights, hall roofs; service and reserve 17,143 17,143 17,143
Estate systems: Standby generator: service contract (2-3 % of the machine a year [68]), monthly test runs under load, fuel turnover; replacement reserve (1.7 M over 25 years) 7,714 7,714 7,714
Estate systems: Stormwater tank, detention meadow and drains: inspection, desilting, outlet 1,429 1,429 1,429
Estate systems: Gate, barriers, LPR, intercom, CCTV, network core: service and reserve 6,429 6,429 5,000 6,429
Estate systems: Transformer and switchgear: maintenance, thermal imaging 2,857 2,857 2,500 2,857
Estate systems: Perimeter trail, green lanes, fitness stations: surface top-up, edging, equipment service, bollard lamps (est.) 4,286 4,286 4,286
Estate systems: Park furniture: table tennis tables, picnic tables, pavilions, benches, hammocks; care and replacement reserve (est.) 2,857 2,857 2,857
Estate systems: PV: inspection, cleaning, monitoring 900 900 900 900 900
Estate systems: Battery: O&M and replacement reserve 13,388 13,388 11,944 18,375 13,388
Electricity: estate PEA bill (houses + common), share 11,750 11,750 6,137 5,898 11,750
Security: contracted guards, share 61,907 61,907 48,150 48,150 61,907
Common services: gardens, pool, cleaning, office 71,121 71,121 48,562 8,000 71,121
Insurance 8,881 10,994 8,881 4,463 8,881 15,200
Land and building tax 34,298 39,246 21,946 13,111 23,323 51,396
less: Electricity above the allowance, billed at the PEA residential rate -3,331 -3,331 -2,659 -3,989 -3,331
Estate systems: Pumps, replacement reserve; water tower inspection, cleaning, repaint reserve 4,583
Estate systems: Pavilion, padel hall, pool and courts: service and reserve 9,167
Estate systems: Standby generator: service contract [68], test runs, fuel turnover; replacement reserve (1.4 M over 25 years) 7,417
Estate systems: Stormwater tank and drains: inspection, desilting 1,000
Maintenance reserve (tenant does the small things) 26,164
Common services 29,138
Full service: AC cleaning, outsourced 6,000
Full service: Technician visits and call-outs (B4L) 30,000
Estate systems: Shared water: filters, UV lamp, lab tests 6,000
Estate systems: Booster set and sewage tanks: service and reserve 5,000
Full service: Private pool: care and chemicals 36,000
Total fixed running costs 462,003 500,278 373,628 121,026 233,241 613,833
per month 38,500 41,690 31,136 10,085 19,437 51,153

Plus 8% management on collected rent and 1 month vacancy a year.

Grouped, THB per house per month:

Line flagship A premium flagship B premium lean A premium lean A standard pilot A premium flagship C premium
Full service: team, consumables, repairs 8,759 9,338 7,754 0 5,317 13,149
Component replacement reserve 8,088 10,110 8,088 2,180 8,088 14,399
Estate systems (water, sewage, grid, battery, PV) 6,268 6,268 4,376 0 2,523 6,268
Electricity (estate PEA bill less excess billed) 702 702 290 0 159 702
Security: contracted guards 5,159 5,159 4,012 4,012 0 5,159
Common services: gardens, pool, cleaning, office 5,927 5,927 4,047 2,428 667 5,927
Insurance and land tax 3,598 4,187 2,569 1,465 2,684 5,550

Gate and security staffing (docs/security-and-access.md)

One guard position = one guard 12 h a day, every day, relief included: 22,500 THB a month plus 7% VAT [45].

Estate Positions Guard positions THB per year Per house per month Normal-spec estate, per house per month
Flagship: 16.9 rai, 14 houses round a natural park, Hang Dong / Nong Khwai area Gate post, 24 h: two guards on 12-hour shifts (2); Night patrol, 18:00 to 06:00 (1) 3 866,700 5,159 3,439
Lean: 6.5 rai, 12 houses round a park, outer Hang Dong / Saraphi Gate post, 24 h: two guards on 12-hour shifts (2) 2 577,800 4,012 4,012
Pilot: 2 houses on a 0.6 rai serviced plot, Hang Dong none (door station calls the houses) 0 0 0 0

Gardens, pool, cleaning and office, whole estate per year (est.):

Item flagship lean pilot
Gardeners, 3 (park, private gardens, verges, green belt and lanes) 491,400
Cleaners, 2: sports centre, changing rooms, guard house, common areas 300,300
Pool chemicals, garden and cleaning materials, standing-water checks 120,000
Estate office: software, phones, access cards and tags, signage 60,000 40,000
Waste collection fee 24,000 15,000
Gardeners, 2 (park and private gardens) 327,600
Cleaner 150,150
Pool chemicals, garden and cleaning materials 50,000
Garden care and cleaning, contractor 16,000
Per house per month 5,927 4,047 667

A normal-spec estate is modelled with the same 24 h gate post and 60% of the gardens, pool, cleaning and office cost.

Density, gardens, park and sports (docs/site-plan.md)

Estate Land (rai) Houses Houses per rai Type A plot Type B plot
Flagship: 16.9 rai, 14 houses round a natural park, Hang Dong / Nong Khwai area 16.9 14 0.8 416 m2 494 m2
Lean: 6.5 rai, 12 houses round a park, outer Hang Dong / Saraphi 6.5 12 1.8 416 m2 494 m2
Pilot: 2 houses on a 0.6 rai serviced plot, Hang Dong 0.6 2 3.3 416 m2 494 m2

Park, sports and stormwater, capital (est.):

Estate Item THB
flagship Stormwater without open water: underground attenuation tank of about 538 m3 under the west meadow of the park (1 m3 per 50 m2 of site [64], about 6,500 THB/m3 [64]), dry detention meadow that drains within a day [62], controlled outlet to the public drain 3,700,000
flagship Sports centre, 540 m2: hall with 2 badminton courts, gym, changing rooms, lobby with co-working; hall as a steel building (turnkey halls from about 8,000 THB/m2 [65]), sports floor [66], gym kit 7,700,000
flagship Pool 20 x 8 m with deck, plant room and shade 2,500,000
flagship Padel courts, 2, with lights (Chiang Mai 400,000 to 800,000 THB per court structure [67]), slab and drainage 1,600,000
flagship Padel hall: enclosed steel hall 24 x 22 m over both courts, 9 m high (FIP: at least 6 m clear over the court, 8 m suggested for new halls [69]), insulated roof, closed walls with louvres, ceiling fans (steel halls from about 8,000 THB/m2 [65]) 4,500,000
flagship Multi-use court 28 x 13 m (futsal, basketball): slab, PU hard court [66], fence, lights 950,000
flagship Natural park, 3,509 m2: native meadow and tree groves, gravel loop of about 153 m, natural play, sala (340 THB/m2 plus 400,000 for play and sala, est.) 1,600,000
flagship Places to sit and play in the park: 1 outdoor table tennis table on a pad (60,000 THB each), 1 picnic lawn with two tables (60,000), 1 shade pavilion with benches (300,000), 1 seating circle (150,000), 9 benches along the loop (12,000), 28 flowering shrubs (1,500), 25 park trees (6,000 planted); all est. 870,000
flagship Perimeter trail, 606 m round the estate in the green belt: 2.5 m permeable running surface on a compacted base with edging (about 900 THB/m2, est.), low bollard lights every 25 m (15,000 THB each, est.); green lanes between the plots, 4 lanes, 4 m wide with a 1.5 m path, 104 m (est.); 10 outdoor fitness stations on the trail and in the park (60,000 THB each, est.) 2,510,000
flagship Total; per house 25,930,000; 1,852,143
lean Stormwater: underground attenuation tank of about 160 m3, dry detention lawn [62][64] 1,200,000
lean Sports pavilion with gym and changing rooms, pool, one padel court, multi-use court 5,000,000
lean Padel hall: enclosed steel hall 12 x 22 m over the court, 9 m high [69][65] 2,300,000
lean Park: lawn, trees, paths, playground 1,000,000
lean Total; per house 9,500,000; 791,667

There is no open water on the estate: stormwater goes to a closed tank under the west meadow of the park and a detention meadow that is dry within a day, so nothing holds standing water long enough for mosquito larvae [62][63].

Flagship site quantities, measured on the layout (scripts/layout.py):

Quantity Value
Site 27,054 m2
8 A, 2 B, 4 C plots (A 16 x 26 m, B 19 x 26 m, C corner plots) 7,904 m2
of which private gardens 2,736 m2
Ring road, roundabouts, gate throat, club spur and car park 3,740 m2
Natural park inside the ring 3,509 m2
Sports centre, padel hall, pool deck, multi-use court 1,744 m2
Frontage strip, service yard with the water tower 1,137 m2
Verges, corner greens, perimeter belt 9,020 m2
Ring road centre line 316 m
Perimeter wall 658 m
Park loop path 153 m
Stormwater tank 538 m3

Site 167 x 162 m = 16.9 rai. Neighbouring houses stand 7 m apart (3.5 m from each side wall to the plot line).

Component replacement reserve, Type A (full service)

Component Cost Life (years) Per year
Air conditioners, 4 units 160,000 12 13,333
ERV unit: fans, core, controls 120,000 15 8,000
Heat pump water heater 90,000 12 7,500
PV string inverter 30,000 12 2,500
Appliances: fridge, hob, oven, washer, dryer, dishwasher 150,000 11 13,636
Interior repaint and touch-ups between tenancies 50,000 4 12,500
Exterior render repaint incl. scaffold 90,000 12 7,500
Roof coating, sealants, window and door gaskets 50,000 15 3,333
Kitchen and bathroom refresh: fronts, tops, fittings 250,000 20 12,500
Sensors, Home Assistant hub, network gear 40,000 8 5,000
EV charger 45,000 12 3,750
Garage door motor, springs and seals 25,000 10 2,500
Blinds and insect screens 40,000 8 5,000
Total 97,053

Type B: x1.25; Type C: x1.6 plus the private pool (17,500 a year: pump, filter and salt cell every 8 years, resurfacing every 15, est.). Structure, windows and PV modules (25+ years) are not reserved.

Rent the house has to earn (monthly; premium all-inclusive)

Line flagship A premium flagship B premium lean A premium lean A standard pilot A premium flagship C premium
Fixed running costs per year 462,003 500,278 373,628 121,026 233,241 613,833
Net yield 4% 124,000 136,000 88,000 41,000 69,000 168,000
Net yield 5% 144,000 158,000 101,000 48,000 80,000 194,000
Net yield 6% 163,000 180,000 114,000 56,000 91,000 221,000
Bank-financed, DSCR 1.25 (60% LTV, 6.5%, 20 y) 179,000 198,000 124,000 61,000 100,000 243,000
Gross yield at 5% net rent 8.7% 8.6% 9.3% 7.9% 8.3% 8.6%

The standard house is let the normal way: the tenant pays electricity, water and small repairs.

What the all-inclusive rent covers (monthly, priced as a tenant would pay)

Included THB/month
Electricity, reference family (450 kWh) at the PEA residential tariff [33] 1,992
Water, 22 m3 at the PWA residential tariff [43] 300
AC cleaning, 4 units x 3 a year at 450 THB [39] 450
Repairs, filters, consumables a tenant would normally carry (est.) 500
Garden care (est.) 1,000
Total 4,242

A tenant in a normal house pays on top of rent:

Tenant's own costs, normal house THB/month
Electricity, 800 kWh at the PEA residential tariff [33] 3,708
Water, 22 m3 at the PWA residential tariff [43] 300
AC cleaning, 4 units x 3 a year at 450 THB [39] 450
Small repairs and consumables (bulbs, washers, pump service) 500
Air purifier filters and power, smoke season, averaged 400
Garden care 1,000
Total 6,358
Monthly occupancy cost to the tenant THB
Standard house (lean): rent for 5 % net + own costs 48,300 + 6,358 = 54,600
flagship A premium: all-inclusive rent for 5 % net 143,800 (bare-rent equivalent 139,600)
lean A premium: all-inclusive rent for 5 % net 100,900 (bare-rent equivalent 96,700)
pilot A premium: all-inclusive rent for 5 % net 79,900 (bare-rent equivalent 75,700)

Project totals, premium spec

Estate Houses Capital, all-in Rent roll at 5 % net rents, per year Equity if bank lends 50 %
Flagship: 16.9 rai, 14 houses round a natural park, Hang Dong / Nong Khwai area 14 311.31 M 26.94 M 155.66 M
Lean: 6.5 rai, 12 houses round a park, outer Hang Dong / Saraphi 12 155.41 M 14.53 M 77.70 M
Pilot: 2 houses on a 0.6 rai serviced plot, Hang Dong 2 23.01 M 1.92 M 11.51 M

Sensitivity: flagship Type A premium

Case All-in cost Running costs / yr Rent for 5 % net Change in rent
Base case 19,870,000 462,000 144,000 +0
Land 3.0 M THB/rai (outer Hang Dong) 17,740,000 456,000 133,000 -11,132
Land 6.5 M THB/rai (prime road frontage) 21,880,000 468,000 154,000 +10,513
No central battery (no estate backup) 19,570,000 460,000 142,000 -1,701
No standby generator (battery and roofs only in a long outage) 19,720,000 454,000 142,000 -1,503
Full 10 kWp on every roof, no export 20,000,000 457,000 144,000 +127
Full 10 kWp on every roof, export at 2.2 THB/kWh 20,000,000 447,000 143,000 -830
Full-service costs 25 % higher 19,870,000 531,000 151,000 +6,852
Full-service costs 25 % lower 19,870,000 393,000 137,000 -6,852
Electricity metered and billed at the PEA residential rate, no allowance 19,870,000 434,000 141,000 -2,725
No sports hall: gym in a small pavilion, outdoor courts only (-5.0 M) 19,430,000 462,000 142,000 -2,179
Padel courts in the open, no padel hall (-4.5 M) 19,480,000 462,000 142,000 -1,961
One padel court and a smaller park (-1.6 M) 19,730,000 462,000 143,000 -697
No night patrol: gate post only 19,870,000 441,000 142,000 -2,039
Guards 20 % cheaper (Chiang Mai quote) 19,870,000 450,000 143,000 -1,223
Second gate, unstaffed: residents only, video call to the main gate 19,950,000 462,000 144,000 +392
Second gate, staffed 24 h 19,990,000 503,000 148,000 +4,645
Open carport instead of the attached garage 19,300,000 457,000 141,000 -3,322
Smaller house, 160 m2 GFA 19,390,000 460,000 141,000 -2,542
Contingency 15 % instead of 10 % 20,520,000 462,000 147,000 +3,188
Value-engineered: land 4.0 M, no battery, no EV charger, no sports hall 18,120,000 457,000 135,000 -9,122

Reverse view: maximum all-in cost for a given rent (5 % net)

Same running costs as the flagship Type A premium house. Useful to test design-to-cost targets.

Monthly rent Max all-in cost vs flagship A premium
50,000 880,000 -96%
60,000 2,900,000 -85%
70,000 4,930,000 -75%
80,000 6,950,000 -65%

What the premium spec and full service cost (lean estate, Type A)

Estate energy: shared grid, central battery (base configuration)

Hourly simulation over 2019-2023 (PVGIS, Hang Dong) in model/estate_energy.py. Loads are estimates.

flagship lean pilot
Houses 14 12 2
PV, kWp total 84 72 12
Central battery, kWh 170 130 30
PEA tariff tou tou tiered
PV generation, MWh/yr 118.5 101.6 16.9
Houses' use, MWh/yr 95.2 69.2 13.0
Common loads (water plant, sewage, pool, sports centre, lights, gate), MWh/yr 52.6 30.9 4.6
Bought from PEA, MWh/yr 35.9 16.1 2.7
PV curtailed (no export), MWh/yr 3.5 14.6 1.4
Share of the estate's use met by its own PV 76% 84% 85%
Share of the PV the estate uses 97% 86% 92%
PEA bill per year, THB (incl. demand charge, Ft, VAT) 164,495 73,649 11,796
PEA bill per house per month, THB 979 511 491

PEA tariff: tou = type 3.2.2 medium business TOU at 22-33 kV; tiered = type 2 small business, same tiers as residential 1.1.2 [33]. Both to be confirmed with PEA.

PV and battery sizing, flagship (annual cost of energy, THB)

Annualised capital (5 %, PV 25 years, battery 15 years) + O&M + PEA bill - export income. In brackets: share of the estate's use met by its own PV.

No export (base)

PV per house battery 0 kWh battery 100 kWh battery 200 kWh battery 300 kWh
0 kWp 634,000 (-0%) 918,000 (0%) 1,068,000 (0%) 1,219,000 (0%)
4 kWp 487,000 (46%) 724,000 (53%) 874,000 (53%) 1,024,000 (53%)
6 kWp 518,000 (52%) 684,000 (69%) 786,000 (76%) 933,000 (77%)
8 kWp 567,000 (54%) 714,000 (74%) 773,000 (88%) 907,000 (91%)
10 kWp 621,000 (56%) 762,000 (76%) 809,000 (92%) 936,000 (97%)

Export at 2.2 THB/kWh

PV per house battery 0 kWh battery 100 kWh battery 200 kWh battery 300 kWh
0 kWp 634,000 (-0%) 918,000 (0%) 1,068,000 (0%) 1,219,000 (0%)
4 kWp 462,000 (46%) 724,000 (53%) 874,000 (53%) 1,024,000 (53%)
6 kWp 425,000 (52%) 653,000 (69%) 781,000 (76%) 930,000 (77%)
8 kWp 395,000 (54%) 613,000 (74%) 722,000 (88%) 867,000 (91%)
10 kWp 368,000 (56%) 582,000 (76%) 685,000 (92%) 828,000 (97%)

Shared grid vs every house on its own (flagship)

Islanded: each house its own PEA residential meter, 10 kWp and a 15 kWh battery; common loads on a separate meter without PV. Hybrid inverter premium 40,000 THB per house (est.); home batteries 15,000 THB/kWh [10], 12-year life.

Design Capital, PV + batteries PEA bills / yr Export income / yr Annual cost of energy
Islanded, 10 kWp + 15 kWh each, no export 7.91 M 250,623 0 1,025,000
Islanded, 10 kWp + 15 kWh each, net billing 7.91 M 250,623 227,637 798,000
Shared grid, 6 kWp each + 170 kWh central, no export 6.01 M 164,495 0 745,000
Shared grid, 10 kWp each + 170 kWh central, no export 7.70 M 76,644 0 785,000
Shared grid, 10 kWp each + 170 kWh central, export 7.70 M 76,644 135,541 649,000

With 7 tenant EVs smart-charged at home (16.4 MWh/yr, billed to the tenants), the share of the estate's use met by its own PV goes from 76% to 70% and curtailment from 3.5 to 1.1 MWh/yr.

Tenant view: electricity