Site plan and house types (rough sketch)

Status: concept sketch, 27 Sep 2026, revised 21 Oct 2026 (utility yard, energy centre, shared networks; frontage strip and main gate; attached garages; 9 m gardens, a park and a sports centre, no open water; enclosed padel hall, standby generator; third layout: 7 m between houses, a round ring road with two roundabouts, a natural park in the middle, the club at the edge, a water tower; sized to a 20,000 m² parcel, 14 houses), revised 3 Nov 2026 (corner houses as Type C with a private pool, an 8 m green belt with a perimeter trail, green lanes between the plots, outdoor fitness stations, places to sit and play in the park; the parcel grows to 16.9 rai). The geometry is in scripts/layout.py, drawn by scripts/sketches.py; the cost model reads its quantities (site, roads, wall, ring length, stormwater tank) and its plot and house sizes are the same numbers. No site has been chosen; the layout shows how 14 houses with gardens (four of them corner houses with private pools) round a natural park, a club, the service yard and a perimeter trail fit on the smallest site the design needs: 27,054 m² (16.9 rai, here 167 × 162 m) with road frontage on one side. Until 3 Nov 2026 the plan was sized to a 20,000 m² (12.5 rai) parcel; for the corner houses, the trail belt and the green lanes the parcel now grows rather than the design losing houses or features. The same design for 20 to 50 houses (19.3 to 34.3 rai) and what that does to the cost per house is in costs-and-rent.md. The same layout as an interactive isometric view, with the houses, garages, gate and utilities in 3D: estate-view.html. Bracketed numbers such as [5] refer to sources.md.

Flagship estate: 27,054 m² (16.9 rai), 14 houses round a natural park

Measured on the layout by scripts/layout.py (also printed by scripts/sketches.py); shares are rounded. Lengths: ring road centre line 316 m, perimeter wall 658 m, perimeter trail 606 m, park loop 153 m, green lanes 4 × 26 m (104 m). 14 houses on 16.9 rai is 0.8 houses a rai, against 1.1 on the 20,000 m² parcel and with 20 houses on the 17.7 rai version of this layout, 1.7 in the second layout (11.8 rai, houses 4 m apart, the sports centre in the park) and 2.5 in the first (8 rai, 3 m gardens, a clubhouse and a pond).

Layout decisions:

• Every house faces north or south. The ridge runs east-west, so each roof has a full south slope for PV and the short east and west walls face the neighbours, not the afternoon sun.
• 7 m between neighbouring houses. Plots are 16 m wide for Type A and 19 m for Type B, and a Type C corner plot at least 26 m, so every house stands 3.5 m from each side line (a corner house from its inner side line): 7 m to the next house, against 4 m before. The side gaps take a path, planting and the plant room's door, and no upper window looks into a neighbour's window at arm's length.
• Every house has its own garden. Each plot runs 6 m garage zone, 11 m house, 9 m garden, so the garden is the full width of the plot: about 144 m² for Type A and 171 m² for Type B, with a hedge to each neighbour. Four rows: 4 houses along the north wall (Type C, Type B, a green lane, Type A, Type C), 3 and 3 Type A inside the ring (two houses, a green lane, one house), the same 4 along the south wall. The two inner rows back onto the natural park, the two outer rows onto the planted belt with the perimeter trail. No house looks into another house's garden, and the estate's gardeners keep every one.
• Corner houses (Type C). The house at each end of the two outer rows takes the whole free corner of the site: its plot runs on to the green belt at the west corners and to within 4 m of the club at the east corners (the gap is a path to the club), 715 to 1,053 m² and 897 m² on average, against 416 m² for a Type A plot. On it stands Type C, the premium+ house: 5 bed, 5 bath, about 300 m² on two storeys, a three-car garage and a private 8 × 4 m pool on the corner side, beside the house at the west corners and in the back garden at the east corners (spec.md §6b). The house keeps 3.5 m from its inner plot line, so it stands 7 m from its neighbour like every other house. Every size of the estate has exactly four.
• A green belt with a perimeter trail. The planted belt inside the wall is 8 m wide (it was 2 m) and carries a 2.5 m running and walking trail of about 606 m all round the estate, lit by low bollard lights. On the west side it runs east of the frontage strip, crosses the gate drive at a marked crossing and meets the path from the pedestrian gate. Outdoor fitness stations (3 × 3 m pads) stand about every 90 m on the inner side of the trail, seven of them, and three more in the park, on free ground at its west and east ends.
• Green lanes between the plots. Lanes 4 m wide with a 1.5 m path run between the plots every 3 to 4 houses: on the outer rows from the ring road through to the trail, on the inner rows from the ring road through to the park. On the flagship that is one lane in every row, four in all (about 104 m): in the middle of each outer row of 4, and after the second house of each inner row of 3. The larger variants have more (costs-and-rent.md, "Estate size").
• A round ring road with two roundabouts. One ring road of about 316 m (8 m reserve) runs round the park. Its shape is a rounded oval rather than a rectangle: the long sides bow gently and the corners are wide curves, so drivers slow down without speed bumps. A roundabout just inside the gate splits arriving traffic both ways round the ring, and a second one at the east end leads to the club car park and the service yard. Each roundabout has a planted island with a tree, inside a concrete apron that the waste truck, the sludge truck and the fire engine can drive over. The rows follow the curve: each plot sits square to north and south (for the PV), set back at least 1 m from the road edge, so the plots step by up to about 2 m along a row and the drives differ a little in length.
• A natural park in the middle. The whole inside of the ring that the houses leave free, about 3,500 m², is a natural park with no buildings in it: a band about 22 m wide between the two inner rows' gardens, widening at both ends of the ring into tree groves. Native meadow mown in paths and edges only, a gravel loop of about 150 m with walks to both roundabouts, natural play with logs and a wooden climbing frame and a small sala inside the loop, and three fitness stations at the park's ends. The dry meadow, a hollow about 0.5 m deep, takes the peak of a heavy storm. On the 20,000 m² parcel it had shrunk to about 2,100 m² (with 20 houses on 17.7 rai it was 4,700 m²); on 16.9 rai it is about 3,500 m².
• Places to sit and play in the park. Besides the sala and the playground inside the loop, the park has four more places to meet in its two wide ends, north and south of the loop: an outdoor concrete table tennis table on a pad with a bench beside it (north-west), a picnic lawn with two tables (north-east), a second shade pavilion with built-in benches (south-west) and a seating circle, low curved benches round a small paved circle (south-east). Shade trees stand at the corners of the picnic lawn and the table tennis pad. Nine benches face the loop path, 28 flowering shrubs (about 1 to 1.5 m high, est.) line the inner rows' garden hedges on the park side and stand beside the places, and 25 trees stand in the park. The larger variants have more: a hammock grove with three hammocks from 30 houses up, and in the longer estates some places inside the loop as well; the 50-house estate has 11 places (three table tennis tables, two each of the others), 34 benches, 82 shrubs and 53 trees in the park (counts from scripts/layout.py). The model prices the flagship's places, benches, shrubs and trees at about 0.87 M (a table tennis table on its pad 60,000, the picnic lawn 60,000, the pavilion 300,000, the seating circle 150,000, a hammock grove 60,000, a bench 12,000, a shrub 1,500, a tree 6,000 planted; all est.) and their care and replacement at about 40,000 THB a year (est.), about 240 THB per house per month (costs-and-rent.md).
• The club sits at the east edge, outside the ring. East of the club roundabout, along the east wall, in one column: the sports centre (540 m²: a closed 18 × 16 m hall with two badminton courts, and an annex with a lobby and co-working, changing rooms and a gym) north of the club car park, the enclosed padel hall (22 × 24 m over two courts, 9 m high: the padel federation asks for at least 6 m clear over the court and suggests 8 m for new halls[69]) south of it, then the 28 × 13 m outdoor multi-use court for futsal and basketball and the 20 × 8 m pool in the south-east corner. Badminton and padel play indoors, through rain and midday sun. The two 9 m halls stand about 26 m from the nearest house and its back garden: at Chiang Mai's December noon sun (about 48° above the horizon) a 9 m wall casts about 8 m. The north-east corner plot's side garden comes within about 14 m of the badminton hall, but it lies north-west of the hall, so the noon shadow falls beside it; only long early-morning shadows in the cool season may reach its far corner (est.).
• A water tower in the service yard. The water plant, the sewage plant and a 50 m³ water tower share a 26 × 26 m service yard in the north-east corner, north of the sports centre, with its own short drive from the ring road for the sludge truck and chemical deliveries. The tower's tank floor stands about 21 m up, which gives about 2 bar at the street by gravity (utilities.md). It is the landmark of the estate; its shadow is slim and moves through the day.
• No open water. The first layout had a retention pond. Mosquitoes need standing water for several days to develop, so a basin that empties within 72 hours does not breed them,[62] and the Aedes mosquitoes that carry dengue breed even in containers holding very little water.[63] The estate therefore keeps its stormwater out of sight: a closed tank of about 540 m³ under the west meadow of the park (1 m³ per 50 m² of site, the on-site retention rate the Bangkok city plan rewards,[64] used here as a benchmark until the local requirement is known) and the dry meadow, which is empty again within a day. The outlet to the public drain is throttled, irrigation comes from treated effluent and a covered rainwater cistern, and the team checks gutters, drains and the tank's access covers every week (utilities.md). The whole estate is still filled above the local flood level (see spec.md §1).
• Lower density costs money. Each Type A house carries about 1,784 m² of land including its share of roads, park, belt and club, against 1,395 m² on the 20,000 m² parcel, 910 m² in the second layout and 616 m² in the first. The club, gate, water plant and generator are shared by 14 houses, so a flagship Type A house costs about 19.9 M all-in and needs about 144,000 THB a month for a 5 % net yield, and a Type C about 27.1 M and 194,000 (costs-and-rent.md). Land price is the strongest single lever (3.0 M a rai instead of 4.8 M: about 11,100 a month less rent for a Type A); with 14 houses the club weighs more on each rent, so the sports hall (about 2,200 a month) and the padel hall (about 2,000) are the next ones to test.
• One gate, one ring, no through traffic. A 10 m frontage strip inside the west wall holds the main gate, seven guest and EV parking bays, the energy centre (E: transformer, main board, central battery, energy management, where the PEA 22 kV line arrives from the public soi), the workshop (W: spare-parts store, staff room, bin store) and the standby generator. The barriers stand 11 m inside the wall, so cars waiting at the gate never stand on the public soi; behind them the drive crosses the perimeter trail at a marked crossing and enters the west roundabout. The gate has two lanes in (residents by plate or card, visitors after the guard has called the house), one lane out and a pedestrian gate (security-and-access.md).
• Service stays at the edges. Parts deliveries, waste collection and contractors' vans stop at the workshop by the gate. The standby generator has its own fenced compound (10 × 10 m) in the frontage strip south of the workshop, where the fuel truck stops near the gate; the nearest house is about 33 m away, beyond the belt and the trail. The service yard has its own drive off the ring at the club end.
• Utilities run in the road reserve. The looped water main and the low-voltage ring follow the ring road, so every house is one short service connection from both, and either network can feed a house from two directions (utilities.md).
• Every house has its garage on the street side. On Type A plots the garage is 1.5 m wider than the house and stops 0.5 m short of the plot line; on Type B it sits within the house's width; Type C has a 9.5 m garage for three cars behind two doors. Residents drive from the gate straight into their own garage, so the estate roads stay clear of parked cars.

Main gate

The gate plan uses the same coordinates as the site plan. How residents, visitors, deliveries and emergency services get in, the intercom, the guards and the costs are in security-and-access.md.

House Type A: 3 bed, 3 bath, 180 m², two storeys, attached garage

• Ground floor 99 m² (9 × 11 m): living and dining along the whole garden side, study, kitchen, guest bath, laundry, entry on the street side.
• Upper floor 81 m² (9 × 9 m): master bedroom with ensuite, two bedrooms, second bathroom.
• Attached garage, 6.5 × 6.0 m, two cars side by side, 7 kW EV charger: single storey, outside the airtight envelope, with a fire-rated, airtight, self-closing door into the laundry and a motorised sectional door to the street (spec.md §6a). The front door is reached by a path between the garage and the plant room.
• Video intercom: a door station at the front door and an indoor station with an SOS button by the entrance, linked to the guard house.
• Plant room outside the envelope, next to the garage: ERV and filters, PV string inverter and house sub-meter, heat pump water heater, water meter with check and leak shut-off valves, main board, fibre. The estate team changes filters and services the equipment without entering the tenant's home. There is no battery, tank or pump at the house: those are shared (utilities.md).
• Type B (4 bed, 240 m²) is the same plan widened to 12 m, with a fourth bedroom and bath on the ground floor, on a 19 × 26 m plot.
• Type C (5 bed, 5 bath, about 300 m²), the corner house, is Type B's plan enlarged to 15 m wide, with a three-car garage (9.5 × 6.0 m) and a private 8 × 4 m pool with deck and fence on the corner side, on a corner plot of 715 to 1,053 m² (spec.md §6b).

The rows whose gardens lie south of the house (the north inner row and the south outer row) use the mirrored plan: the garden and living room face south behind a 2.5 m pergola.

Section: what makes it a premium house

At Chiang Mai's latitude (about 18.8° N) the noon sun stands almost overhead, slightly to the north, in June and about 48° above the southern horizon in December. Deep eaves and a garden-side pergola keep direct sun off the glass for most of the year; the numbered items are specified in spec.md.

Shared utilities

The water main (blue) is fed from the water tower in the service yard and the low-voltage ring (orange) from the energy centre; both follow the ring road. The stormwater tank (dashed) lies under the west meadow of the park. Details and the energy model results are in utilities.md.