What's Behind the Wall: How to Open Up an Older House Without Writing a Blank Check

The fear is not that something will go wrong. The fear is the phone call. Two weeks in, a voice says they found something, and the number you agreed to is suddenly a suggestion.

That call is avoidable, but not by hoping nothing is found. It is avoidable by deciding, before demolition, what happens if something is. This is the difference between discovery and damage, and it is worth being precise about it, because most remodeling arguments come from confusing the two.

Discovery is not damage

Damage is when someone breaks something that was fine. A cracked tile in the hall, a dented door, a nicked pipe. That is on the contractor and should be fixed at their cost without a conversation.

Discovery is when the wall opens and reveals something that was already true. The drain is cast iron. There is no insulation. A previous owner ran the range circuit through the cabinet. Nobody caused it. Nobody could see it. Somebody still has to pay for it.

A good contractor tells you which category a surprise falls into before telling you the price of it. A bad one blurs the line, because a blurred line means you pay for both.

What is actually behind a Houston wall

Houston housing stock has patterns, and knowing them turns most surprises into expectations.

Plumbing that has to move. This is the big one. Relocating a sink or a drain without cutting the slab runs $500 to $1,000. Relocating one that requires cutting and patching the slab runs $1,800 to $5,000, and it is the single biggest surprise line on a Houston kitchen. Anyone moving your sink more than a couple of feet should be telling you which of those two numbers applies, and why they believe it, before you sign.

Electrical that never got updated. Kitchens built before modern code often have far fewer circuits than a current kitchen needs. A dedicated 20 amp circuit is $250 to $900. A new receptacle is $150 to $330. If the whole panel is undersized, upgrading to 200 amp service runs $1,200 to $2,150. Electricians in Houston bill $75 to $150 an hour with a trip minimum of $100 to $200, so small scattered fixes cost more than the parts suggest.

A wall that turns out to be carrying something. Removing a load-bearing wall on a one story slab across an 8 to 20 foot span runs $3,000 to $5,250 in Houston. Longer spans or a two story load run $5,750 to $12,000. A structural engineer’s letter is $300 to $1,200 and is not the place to save money.

A floor that is not flat. Houston sits on expansive clay and slabs move seasonally, so floors here are rarely level. Self-levelling underlayment runs $3 to $6 a square foot, and large format tile is the least forgiving finish you can put over a wavy substrate.

Water where nobody looked. Under the sink, behind the dishwasher, at the base of an exterior wall. This is the discovery that is most likely to grow, because rot follows moisture rather than staying where it started.

Old materials. In houses of a certain age, floor tile, mastic and some insulation warrant testing before demolition rather than after. Testing is cheap. Doing it in the wrong order is not.

Common discoveries and what they cost here

Note what that table shows. Most of what gets called a surprise is not unknowable. It is unasked. An estimator who opens the panel, looks under the sink, and gets an engineer out before quoting a wall removal has converted three quarters of the risk into a number.

How to price the unknown before you sign

Three tools do almost all the work here.

An allowance is a dollar figure carried in the contract for something whose exact cost is not yet fixed, like tile or plumbing fixtures you have not chosen. Allowances should be realistic, not decorative. An allowance set low makes a quote look competitive and guarantees an overage later. Ask what the allowance would buy, in a real product, at a real store.

A contingency is a percentage held back for genuine discovery. It is a pot of money, not a permission slip. The two questions to ask are who decides when it is spent and what happens to what is left. If nobody can answer the second question, assume the answer is that the contractor keeps it.

A named exclusion is the most honest thing on an estimate. A line that says slab cutting for drain relocation is not included, and here is the range if it is needed, tells you far more about a contractor than a lower total does. Quotes that exclude nothing are usually quotes that inspected nothing, which is one of the reasons three bids never actually compare.

When a discovery does happen

There is a right sequence, and you should be able to recite it before work starts. Work stops in that area. You are shown the thing, in person or in a photograph taken that hour. You are told whether it is discovery or damage. You are given a written price and a schedule impact before anything is done about it. You say yes or no in writing.

If any step is skipped, particularly the written price before the work, you have lost the only leverage you had. The mechanics of that process is worth understanding in advance, and change orders, explained walks through it.

There is no way to know everything

A wall is opaque. Anyone who promises no surprises is either not looking or not telling. The realistic goal is not zero surprises, it is a small number of small ones, priced in advance, decided by you.

Judged that way, the contractor who spends an hour with a flashlight and an outlet tester before quoting is cheaper than the one who emailed a number the same afternoon, even when the flashlight quote is higher on paper. You are not comparing prices at that point. You are comparing how much of the job each one has actually looked at, which is the same problem covered in how to actually compare three quotes.

How Haven handles this

We write allowances in plain language. Not a line that says tile allowance and a number, but what that number buys, what it is based on, and what happens if you choose above it. If we think an allowance is set too low to be real, we will say so at the estimate rather than at the invoice.

The contingency works the same way. It is stated as a figure, it is only spent on written, approved discovery, and whatever is not used comes back to you. It is your money sitting in the plan, not ours sitting in the price.

If you want to know what is likely to be behind your walls before you commit to anything, we will come out, open the panel, look under the sink, and put the honest ranges in writing before we leave.