easy · flats · 2 storeys
B0021: a fourplex on a 14.4 × 39.3 m lot
4 dwellings, 24 rooms. No method found a design meeting every constraint within the budget.
Requirements
- Lot
- 14.4 × 39.3 m (566 m²)
- Street side faces
- 255° (0 = north)
- Setbacks front / rear / left / right
- 5.5 / 5.3 / 2.1 / 2.1 m
- Storeys × height
- 2 × 2.8 m
- Shared core
- yes (access gallery + stair)
- Open space, net of parking
- ≥ 30% of the lot
- Parking spaces
- 1
- Courtyard
- not required
- Tightness (programme / buildable volume)
- 0.455
Programme
| Dwelling | Type | Storey | Min m² | Rooms |
|---|---|---|---|---|
| U0 | 2BR | 0 | 63 | entry, living, kitchen, bathroom, bedroom primary, bedroom secondary |
| U1 | 2BR | 0 | 63 | entry, living, kitchen, bathroom, bedroom primary, bedroom secondary |
| U2 | 2BR | 1 | 63 | entry, living, kitchen, bathroom, bedroom primary, bedroom secondary |
| U3 | 2BR | 1 | 63 | entry, living, kitchen, bathroom, bedroom primary, bedroom secondary |
Required contacts: entry–living, kitchen–living. Doors forbidden between: entry–bedroom_primary, entry–bedroom_secondary, kitchen–bathroom.
Results by method
| Method | Solved | HV | Evals | s | Notes |
|---|---|---|---|---|---|
| Heuristic | 0% | 0.000 | 537 | 2.1 | |
| Random search | 0% | 0.000 | 1500 | 6.3 | |
| Simulated annealing | 0% | 0.000 | 1500 | 6.4 | |
| NSGA-II | 0% | 0.000 | 1500 | 7.1 | |
| CP-SAT | 0% | 0.000 | 0 | 4.6 | solver timeout |
| Random sketch + repair | 0% | 0.000 | 1500 | 6.9 | repair collapse |
| Heuristic-seeded NSGA-II | 0% | 0.000 | 1500 | 6.7 | repair collapse |
Mean over 1 seeds (the heuristic is deterministic: one run).
Closest attempts that failed
For methods that found nothing feasible: their least-infeasible design, with its violations marked on its page.
Convergence on this brief
Archive hypervolume against evaluations, mean over seeds.
What stopped designs here
| method | C04 | C05 | C06 | C07 | C08 | C09 | C10 | C11 |
|---|---|---|---|---|---|---|---|---|
| Heuristic | – | 15% | 21% | – | – | 99% | – | 1% |
| Random search | 19% | 100% | 100% | 8% | 54% | 99% | 100% | 99% |
| Simulated annealing | 50% | 87% | 82% | 10% | 18% | 100% | 57% | 78% |
| NSGA-II | 20% | 71% | 58% | 7% | 10% | 99% | 42% | 58% |
| Random sketch + repair | 40% | 73% | 81% | 8% | 10% | 53% | 73% | 74% |
| Heuristic-seeded NSGA-II | 7% | 34% | 48% | 2% | 3% | 100% | 15% | 20% |