Can you get a mortgage on a timber frame house?

The idea that timber frame is hard to mortgage comes from a handful of older building systems and a lot of repetition. For anything built in the last few decades it is out of date. There are still a few things a valuer looks at, and they are worth knowing before you build or buy.

What “standard construction” means

Lenders sort houses into standard and non-standard. Standard used to mean brick or stone walls under a tiled or slated roof. Most lenders now include modern timber frame in that group, because it is built to the same regulations, carries the same warranties and makes up a large share of new homes. In Scotland it is the usual way to build.

Each lender writes its own criteria, so nobody can promise every lender will say yes to every house. In practice a platform-frame house with a brick or rendered outer face goes through on normal terms.

What a valuer looks at

Four things can make a lender hesitate.

Age and system. Some timber-framed systems built between the 1920s and the 1970s have known defects, and a few lenders are wary of anything timber from before about 1970. They may ask for a structural survey.

The outer face. A frame behind brick or render reads as conventional. A house clad entirely in timber boards is more likely to be referred to an underwriter, who will ask what is behind the boards and whether a fire barrier is in place.

Condition. Signs of damp at the base, raised ground levels, or retrofitted cavity wall insulation, which should never be injected into a timber frame cavity.

Paperwork. A new-build warranty for a recent house; a building regulations completion certificate for an extension or alteration.

Does a timber frame extension change anything?

For the mortgage on the house, almost never. The valuer is valuing the whole property, most of which is the original building. An extension is judged on whether it was built with consent and signed off, not on what its walls are made of.

Where it can matter is if the extension is the first thing a surveyor sees and it is fully timber-clad, unusual in shape and without certificates. Then expect questions. The answer is the paperwork.

You are meant to tell your lender before making structural alterations; most mortgage conditions say so. It is normally a formality. If you are borrowing more to pay for the work, the lender will want the plans and costs anyway.

Insurance

Buildings insurers ask how the walls and roof are constructed. Answer accurately. If the main house is brick and the extension is timber frame with a brick or rendered face, many insurers will still class the property as standard, but some ask what proportion is timber frame or has a flat roof.

A few insurers load the premium for timber frame or decline it. Many do not. If your renewal jumps after you declare an extension, a broker will find one of the many that are relaxed about it. What you must not do is leave it off the form; an insurer can refuse a claim if the construction was misdescribed.

During the build, tell your insurer before work starts. Standard policies often exclude damage while the house is open to the weather or scaffolded, and you may need the builder’s cover to fill the gap.

Papers to keep

Put these in one folder and keep it with the deeds.

• Planning permission or a lawful development certificate, if you applied for either.
• Building regulations approval and the completion certificate. In Scotland, the building warrant and the accepted completion certificate.
• The frame maker’s structural calculations and panel drawings.
• Guarantees for the frame, roof membrane, windows and any timber treatment.
• Electrical and gas certificates for the new work.
• Any party wall award.

When you sell, the buyer’s solicitor will ask for most of them. Missing certificates are a far more common cause of delay than the word “timber”.

Buying a house that already has one

Ask the seller for the completion certificate first. If there is none, the extension may have been built without approval, and the choice is between an indemnity policy, a regularisation application to the council, or a lower offer.

Have your surveyor look at the base of the walls, the flashing where the extension roof meets the house, and inside the cupboards against outside walls. Damp there is the thing to walk away from, or to price in.

The short version for builders-to-be

Give the extension an outer face that suits the house, keep the ground 150 mm below the frame, and get the completion certificate. Do those and a lender will treat your timber frame extension like any other part of the building.

Thinking of building one? The quote form under this post takes about a minute.