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: 34.3 rai, 50 houses round a natural park, Hang Dong / Nong Khwai area 34.3237 rai @ 4.80 M/rai 29xA, 17xB, 4xC 164.75 M 118.45 M 2,368,940 530 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) 1,036 1,114 867 867 480 1,485
Land 3,200,993 3,442,013 1,394,792 1,394,792 1,854,000 4,588,403
Estate infrastructure share (incl. shared grid, battery, water plant) 2,368,940 2,368,940 2,877,917 1,787,667 1,325,000 2,368,940
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 793,291 931,765 839,098 303,490 699,336 1,206,229
Contingency 960,763 1,128,470 1,016,242 375,316 846,974 1,460,877
Finance during build 413,082 475,656 377,203 213,953 335,121 619,741
Total all-in 14,182,468 16,330,843 12,950,652 7,345,717 11,505,831 21,277,790
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 61,008 53,703 64,199 33,061 53,621 55,631

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 (118.45 M THB, 50 houses)

Line THB
Land fill (flood margin) and grading 14,900,000
Ring road and two roundabouts, 6,465 m2: kerbs, drainage, landscaped islands with mountable aprons for trucks 14,900,000
Stormwater without open water: underground attenuation tank of about 1095 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 7,300,000
Central battery, LFP 530 kWh 7,155,000
Estate grid: 22 kV connection and metering, transformer, main LV board, LV ring of about 657 m to every house, revenue-grade sub-meters 8,900,000
Battery inverter (grid-forming), energy management system, islanding switchgear, fire-rated battery room 2,580,000
Standby generator: sized for 50 houses, scaled from the 14-house estate (est.) 3,650,000
Water plant: sized for 50 houses, scaled from the 14-house estate (est.) 4,940,000
Water tower: sized for 50 houses, scaled from the 14-house estate (est.) 2,150,000
Water ring main of about 657 m, house connections, smart meters, hydrants 2,100,000
Irrigation from treated effluent and a covered rainwater cistern (no open water) 1,290,000
Central sewage treatment plant 3,860,000
Fibre backbone, network core, common-area Wi-Fi 1,930,000
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 792,000
Perimeter wall of 1002 m with anti-climb top, gate throat and islands, guard house with parcel room 6,000,000
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, 8,882 m2: native meadow and tree groves, gravel loop of about 491 m, natural play, sala (340 THB/m2 plus 400,000 for play and sala, est.) 3,400,000
Places to sit and play in the park: 3 outdoor table tennis tables on pads (60,000 THB each), 2 picnic lawns with two tables (60,000), 2 shade pavilions with benches (300,000), 2 seating circles (150,000), 2 hammock groves (60,000), 34 benches along the loop (12,000), 82 flowering shrubs (1,500), 53 park trees (6,000 planted); all est. 2,170,000
Perimeter trail, 950 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, 10 lanes, 4 m wide with a 1.5 m path, 260 m (est.); 14 outdoor fitness stations on the trail and in the park (60,000 THB each, est.) 4,000,000
Common landscaping: verges and corner greens (12,770 m2, mostly native meadow at about 150 THB/m2), trees, street lighting 4,100,000
Workshop, spare-parts store, staff room and bin store by the gate 800,000
Permits: building, environmental screening, PEA, groundwater, utility connections 3,430,000

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) 46,969 46,969 65,248 46,969
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 3,800 3,800 5,000 3,800
Estate systems: Transfer and well pumps, replacement reserve (360,000 over 12 years) 1,200 1,200 1,200
Estate systems: Water tower: yearly inspection and tank cleaning; repaint reserve (300,000 every 10 years) 2,000 2,000 2,000
Estate systems: Sewage plant: service, sludge removal, blower reserve 3,800 3,800 5,000 3,800
Estate systems: Sports centre, padel hall, pool and courts: AC, fans, sports floor, padel glass and turf, nets, lights, hall roofs; service and reserve 4,800 4,800 4,800
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) 4,600 4,600 4,600
Estate systems: Stormwater tank, detention meadow and drains: inspection, desilting, outlet 820 820 820
Estate systems: Gate, barriers, LPR, intercom, CCTV, network core: service and reserve 1,800 1,800 5,000 1,800
Estate systems: Transformer and switchgear: maintenance, thermal imaging 1,800 1,800 2,500 1,800
Estate systems: Perimeter trail, green lanes, fitness stations: surface top-up, edging, equipment service, bollard lamps (est.) 1,880 1,880 1,880
Estate systems: Park furniture: table tennis tables, picnic tables, pavilions, benches, hammocks; care and replacement reserve (est.) 2,200 2,200 2,200
Estate systems: PV: inspection, cleaning, monitoring 900 900 900 900 900
Estate systems: Battery: O&M and replacement reserve 11,686 11,686 11,944 18,375 11,686
Electricity: estate PEA bill (houses + common), share 6,178 6,178 6,137 5,898 6,178
Security: contracted guards, share 23,112 23,112 48,150 48,150 23,112
Common services: gardens, pool, cleaning, office 35,182 35,182 48,562 8,000 35,182
Insurance 8,881 10,994 8,881 4,463 8,881 15,200
Land and building tax 27,364 32,313 21,946 13,111 23,323 44,166
less: Electricity above the allowance, billed at the PEA residential rate -2,875 -2,875 -2,659 -3,989 -2,875
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 310,951 349,226 373,628 121,026 233,241 462,484
per month 25,913 29,102 31,136 10,085 19,437 38,540

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 6,231 6,810 7,754 0 5,317 10,621
Component replacement reserve 8,088 10,110 8,088 2,180 8,088 14,399
Estate systems (water, sewage, grid, battery, PV) 3,441 3,441 4,376 0 2,523 3,441
Electricity (estate PEA bill less excess billed) 275 275 290 0 159 275
Security: contracted guards 1,926 1,926 4,012 4,012 0 1,926
Common services: gardens, pool, cleaning, office 2,932 2,932 4,047 2,428 667 2,932
Insurance and land tax 3,020 3,609 2,569 1,465 2,684 4,947

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: 34.3 rai, 50 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 (2) 4 1,155,600 1,926 963
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, 6 (park, private gardens, verges, green belt and lanes) 982,800
Cleaners, 2: sports centre, changing rooms, guard house, common areas 300,300
Pool chemicals, garden and cleaning materials, standing-water checks 260,000
Estate office: software, phones, access cards and tags, signage 130,000 40,000
Waste collection fee 86,000 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 2,932 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: 34.3 rai, 50 houses round a natural park, Hang Dong / Nong Khwai area 34.3 50 1.5 416 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 1095 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 7,300,000
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, 8,882 m2: native meadow and tree groves, gravel loop of about 491 m, natural play, sala (340 THB/m2 plus 400,000 for play and sala, est.) 3,400,000
flagship Places to sit and play in the park: 3 outdoor table tennis tables on pads (60,000 THB each), 2 picnic lawns with two tables (60,000), 2 shade pavilions with benches (300,000), 2 seating circles (150,000), 2 hammock groves (60,000), 34 benches along the loop (12,000), 82 flowering shrubs (1,500), 53 park trees (6,000 planted); all est. 2,170,000
flagship Perimeter trail, 950 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, 10 lanes, 4 m wide with a 1.5 m path, 260 m (est.); 14 outdoor fitness stations on the trail and in the park (60,000 THB each, est.) 4,000,000
flagship Total; per house 34,120,000; 682,400
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 54,918 m2
29 A, 17 B, 4 C plots (A 16 x 26 m, B 19 x 26 m, C corner plots) 23,920 m2
of which private gardens 8,280 m2
Ring road, roundabouts, gate throat, club spur and car park 6,465 m2
Natural park inside the ring 8,882 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 12,770 m2
Ring road centre line 657 m
Perimeter wall 1,002 m
Park loop path 491 m
Stormwater tank 1,095 m3

Site 339 x 162 m = 34.3 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 310,951 349,226 373,628 121,026 233,241 462,484
Net yield 4% 87,000 99,000 88,000 41,000 69,000 130,000
Net yield 5% 101,000 115,000 101,000 48,000 80,000 151,000
Net yield 6% 115,000 131,000 114,000 56,000 91,000 172,000
Bank-financed, DSCR 1.25 (60% LTV, 6.5%, 20 y) 126,000 144,000 124,000 61,000 100,000 189,000
Gross yield at 5% net rent 8.5% 8.5% 9.3% 7.9% 8.3% 8.5%

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 100,800 (bare-rent equivalent 96,600)
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: 34.3 rai, 50 houses round a natural park, Hang Dong / Nong Khwai area 50 774.03 M 65.82 M 387.01 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 14,180,000 311,000 101,000 +0
Land 3.0 M THB/rai (outer Hang Dong) 12,950,000 307,000 94,000 -6,464
Land 6.5 M THB/rai (prime road frontage) 15,350,000 314,000 107,000 +6,105
No central battery (no estate backup) 13,940,000 312,000 100,000 -1,041
No standby generator (battery and roofs only in a long outage) 14,090,000 306,000 100,000 -900
Full 10 kWp on every roof, no export 14,310,000 310,000 101,000 +510
Full 10 kWp on every roof, export at 2.2 THB/kWh 14,310,000 295,000 100,000 -894
Full-service costs 25 % higher 14,180,000 364,000 106,000 +5,265
Full-service costs 25 % lower 14,180,000 258,000 96,000 -5,265
Electricity metered and billed at the PEA residential rate, no allowance 14,180,000 286,000 98,000 -2,510
No sports hall: gym in a small pavilion, outdoor courts only (-5.0 M) 14,060,000 311,000 100,000 -610
Padel courts in the open, no padel hall (-4.5 M) 14,070,000 311,000 100,000 -549
One padel court and a smaller park (-1.6 M) 14,140,000 311,000 101,000 -195
No night patrol: gate post only 14,180,000 299,000 100,000 -1,142
Guards 20 % cheaper (Chiang Mai quote) 14,180,000 306,000 100,000 -457
Second gate, unstaffed: residents only, video call to the main gate 14,200,000 311,000 101,000 +110
Second gate, staffed 24 h 14,210,000 317,000 102,000 +730
Open carport instead of the attached garage 13,610,000 306,000 97,000 -3,322
Smaller house, 160 m2 GFA 13,700,000 309,000 98,000 -2,542
Contingency 15 % instead of 10 % 14,680,000 311,000 103,000 +2,445
Value-engineered: land 4.0 M, no battery, no EV charger, no sports hall 13,210,000 311,000 96,000 -4,819

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 3,900,000 -72%
60,000 5,920,000 -58%
70,000 7,950,000 -44%
80,000 9,970,000 -30%

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 50 12 2
PV, kWp total 300 72 12
Central battery, kWh 530 130 30
PEA tariff tou tou tiered
PV generation, MWh/yr 423.3 101.6 16.9
Houses' use, MWh/yr 312.8 69.2 13.0
Common loads (water plant, sewage, pool, sports centre, lights, gate), MWh/yr 100.8 30.9 4.6
Bought from PEA, MWh/yr 71.0 16.1 2.7
PV curtailed (no export), MWh/yr 68.2 14.6 1.4
Share of the estate's use met by its own PV 83% 84% 85%
Share of the PV the estate uses 84% 86% 92%
PEA bill per year, THB (incl. demand charge, Ft, VAT) 308,924 73,649 11,796
PEA bill per house per month, THB 515 511 491

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 1,756,000 (-0%) 2,194,000 (0%) 2,344,000 (0%) 2,494,000 (0%)
4 kWp 1,479,000 (44%) 1,786,000 (51%) 1,826,000 (57%) 1,886,000 (62%)
6 kWp 1,651,000 (48%) 1,946,000 (56%) 1,964,000 (63%) 1,973,000 (70%)
8 kWp 1,851,000 (50%) 2,144,000 (57%) 2,155,000 (65%) 2,155,000 (72%)
10 kWp 2,061,000 (51%) 2,355,000 (58%) 2,362,000 (66%) 2,360,000 (73%)

Export at 2.2 THB/kWh

PV per house battery 0 kWh battery 100 kWh battery 200 kWh battery 300 kWh
0 kWp 1,756,000 (-0%) 2,194,000 (0%) 2,344,000 (0%) 2,494,000 (0%)
4 kWp 1,263,000 (44%) 1,639,000 (51%) 1,735,000 (57%) 1,838,000 (62%)
6 kWp 1,157,000 (48%) 1,526,000 (56%) 1,615,000 (63%) 1,692,000 (70%)
8 kWp 1,062,000 (50%) 1,431,000 (57%) 1,515,000 (65%) 1,587,000 (72%)
10 kWp 972,000 (51%) 1,340,000 (58%) 1,422,000 (66%) 1,494,000 (73%)

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 28.25 M 470,646 0 3,237,000
Islanded, 10 kWp + 15 kWh each, net billing 28.25 M 470,646 858,920 2,378,000
Shared grid, 6 kWp each + 530 kWh central, no export 18.73 M 308,924 0 2,076,000
Shared grid, 10 kWp each + 530 kWh central, no export 24.73 M 189,340 0 2,413,000
Shared grid, 10 kWp each + 530 kWh central, export 24.73 M 189,340 710,617 1,702,000

With 25 tenant EVs smart-charged at home (58.4 MWh/yr, billed to the tenants), the share of the estate's use met by its own PV goes from 83% to 78% and curtailment from 68.2 to 41.2 MWh/yr.

Tenant view: electricity