If you own a duplex in the Heights or a 20-unit garden complex near 610, you already know the hardest part of a remodel is not picking tile. It is getting a budget you can trust before you call three contractors.

We built the Ambient Interiors Houston Estimator for exactly that moment. It starts with real Houston per-room costs, then lets you answer five quick questions to shape the number to your building. You get a live total in under 60 seconds, not a generic national average.

What to expect when you use it

First, you will see the Houston baseline cards at the top. That is our starting point before you touch anything:

• Full gut interior: $80 to $100 per sq ft for affordable finishes, $125 per sq ft for what Sweeten calls the "ideal" finish level, up to $250 per sq ft for high end
• Kitchens: $10,000 to $15,000 budget refresh, $25,000 to $30,000 mid-grade, $40,000 plus for full gut
• Bathrooms: $8,000 to $15,000 budget, $15,000 to $25,000 mid (Remodeling Magazine puts Houston at about $19,000), $30,000 plus for high end
• Living and bedrooms: priced by square footage for paint, flooring, and trim

Art is intentionally excluded. We also factor Harris County permit basics, about $130 for the residential permit plus $100 for plumbing and $100 for mechanical per unit.

How to use this estimator in 3 steps

1. Pick your path. This is the biggest price driver.

• Light Interior Refresh: Choose this if you are keeping walls, plumbing, and electrical where they are. We assume no to questions 6 through 20 from our full 20-question checklist. Think paint, floors, new cabinets and fixtures in the same footprint.
• Full Gut Remodel: Choose this if you are moving wet walls, rewiring, repiping, touching HVAC, or opening up structure. We assume yes to questions 6 through 20.

2. Answer the five questions that actually move the math.

• Q1 Location: Standard Harris County, Floodplain, or Historic/Inner Loop
• Q2 Building age and type: 2000s garden-style, 1980s to 1999, 1960s to 1979, or pre-1960/concrete mid-rise
• Q3 Scale: How many units and total interior square footage
• Q4 Scope confirmation: already handled by your path choice
• Q5 Rooms included: kitchens per unit, baths per unit, and whether to include living areas

Each answer updates the total instantly. No form submit, no email wall.

3. Read your live breakdown.

You get total project cost, cost per unit, cost per sq ft, plus the line items for general areas, kitchens, baths, permits, and contingency. Use it to compare scenarios, like a 1960s 6-plex versus a 2010 build.

Details on how we did it

We did not pull a national calculator and change the city name. We built two separate formulas from Houston multifamily data.

The Light path formula:

• Base rate of $45 per sq ft for general areas (paint, flooring, trim, minor drywall)
• Flat kitchen at $12,500 and flat bath at $11,500 (the midpoints of Houston budget ranges)
• 10% contingency because surprises are smaller when you are not opening walls

The Full path formula:

• Base rate of $95 per sq ft (midpoint of the $80 to $100 Houston gut range)
• Flat kitchen at $27,500 and flat bath at $20,000 (mid-grade gut midpoints)
• 15% contingency for the unknowns behind the drywall

Then we apply what really changes Houston pricing:

• Location multiplier (L): Floodplain adds about 10% for inspections and labor logistics. Historic or Inner Loop adds about 15% for parking, restricted hours, and design review.
• Age and type multiplier (A): Newer wood frame gets a 5% discount. A 1960s to 1979 building adds about 12% for lead, asbestos risk, and uneven framing. Pre-1960 or concrete adds about 22%.
• Economy of scale: 1 unit is baseline, 2 to 3 units is neutral, 4 to 9 units saves about 4%, 10 plus units saves about 8% because of repeat rooms and bulk buying.
• Permits: We add roughly $330 per unit times your location factor, so you do not get surprised at the counter.

The math looks like this behind the scenes: we calculate your general-area square footage by subtracting estimated kitchen and bath footprints, multiply by the adjusted per-sq-ft rate, add your flat kitchens and baths, apply the scale discount, add permits, then add contingency. That is your total.

Why we limited it to five questions

Our full pre-construction checklist has 20 questions, from structural changes to tenant phasing. Answering all 20 gets you within about 10% of final cost. Most owners are not ready for that on a first visit.

So we front-loaded the five that swing the budget the most in Houston multifamily: where you are, how old the building is, how big it is, whether it is a gut, and exactly what rooms count. That gets you from a plus or minus 30% guess to a plus or minus 15 to 20% working budget. Good enough to decide if you should move to drawings.

What this number includes, and what it does not

Includes: demolition, new finishes, standard cabinets, vanities, plumbing and lighting fixtures, flooring, paint, trim, typical electrical and plumbing in place for Light, full rough-in for Full, plus Houston-area labor and the permit fees noted above.

Does not include: art, furniture, window treatments unless you check them, structural engineering, abatement for major mold or asbestos, common-area work, tenant relocation, or lost rent during construction. Those are the items that push a project from the estimator to a real proposal.