Journal · 1 min read
How Much Does a Whole-House Renovation Really Cost?
A per-square-metre breakdown of Bangkok renovation costs, plus how to set a buffer that keeps the budget from blowing out.
2026-04-07
A whole-house renovation in Bangkok in 2026 typically runs 8,000 to 20,000 THB per square metre, depending on the existing condition and material grade. A full townhouse often lands at 500,000 to 1.5 million THB, a detached house from 1 million up. Always reserve a 10 to 20 percent contingency.
Cost per square metre by scope
Renovation splits roughly into three tiers. A surface refresh (paint, new flooring, new lighting) sits around 3,000 to 6,000 THB per square metre. A mid-scope job that adds bathroom and kitchen rework moves to 8,000 to 12,000 THB. Structural changes or extensions push past 15,000 THB.
What quietly blows the budget
The costs people forget sit behind the walls. Once you open them up, older homes (especially those over 15 years) tend to reveal problems that must be fixed on the spot.
- Old wiring and plumbing that need a full re-run
- Leaks and mould found once the ceiling comes down
- Debris removal and disposal (truck plus dump fees)
- Change orders when you revise the plan mid-build
How to set a budget you can hold
Start by locking the scope before you shop for a contractor. Name material models and brands in the contract, ring-fence a separate 15 percent buffer, and pay in stages tied to completed work. Avoid large upfront lump sums, so you keep control of both quality and cash flow.
How long does a full townhouse renovation take?
A surface refresh takes about 3 to 5 weeks. A job that includes bathrooms, kitchen, and systems usually runs 2 to 4 months, depending on site conditions and any special-order materials.
Renovate or rebuild, which is more worth it?
If the structure is sound and the layout works, renovating is usually 30 to 50 percent cheaper than rebuilding. If you need to gut nearly the whole layout, price a new build alongside it before deciding.