What is non-standard construction? Meaning, types and how to tell

01What non-standard construction means

There is no single legal definition. Each lender sets its own. Leeds Building Society, for example, describes a standard home as having solid walls of at least 230mm or cavity walls of at least 280mm, built in brick, natural or reconstituted stone, concrete block, cob or flint, with a conventional roof (Leeds BS criteria). A home that falls outside its lender's description is "non-standard" for that lender.

"Non-traditional construction" means much the same thing and is the more common phrase in Scotland and in official statistics. The English Housing Survey, for instance, counts as non-traditional any home with a concrete or steel load-bearing structure (English Housing Survey 2011).

02The main types of non-standard house

03Non-standard is not the same as "defective"

Some types are designated defective under the housing defects legislation, now Part XVI of the Housing Act 1985 (Housing Act 1985 Part XVI). The national list of designated types, which applies in England and Wales, includes Airey, Cornish Unit, Orlit, Reema Hollow Panel, Unity and Butterley, Woolaway and others (Hansard, 7 Feb 1989; SI 1988/923). Many other non-standard types, such as Wimpey No-Fines and BISF, are not on that list. Our free resources page has the full list.

04Is my house non-standard construction?

Signs that it might be:

• It was built between about the 1920s and the 1970s, particularly as council housing.
• The outside walls are rendered concrete, concrete panels, or metal or tile cladding, rather than visible brick or stone.
• Neighbouring houses on the estate share an unusual look, or some have been refaced in brick while others haven't.
• An earlier survey, the title, or the sales particulars mention a system name.
• A lender's valuer has asked for a specialist or structural report.

Looks can mislead: many concrete and steel houses have been refaced to look traditional. Our house-type guides explain the clues for each type, and a surveyor can confirm it.

05Why it matters

• Mortgages. Some types are widely accepted, some need extra evidence, and some are declined by many lenders. See the mortgage guide.
• Repairs and paperwork. Designated PRC homes usually need evidence of an accepted repair, and often the same for the attached home.
• Insurance. Most home insurers treat brick, stone or concrete walls with a slate, tile or concrete roof as "standard construction". Other materials, such as steel or timber frames, can make a home harder to insure (Homeprotect). Some lenders won't lend if buildings insurance can't be arranged on standard terms (TSB criteria).
• Selling. A buyer's lender will spot the construction, so having the facts and paperwork ready keeps a sale moving.

06How common are non-standard homes?

England's housing survey counted about 1,208,000 non-traditional homes in 2011, 5.3% of the stock (EHS 2011). In Wales, 8% of dwellings were non-traditional in 2017-18: 4% timber or steel frame and 4% concrete (WHCS 2017-18). So proportionally, the question comes up more often in Wales than in England.

07What to do next

1. Find your likely type in our house-type guides.
2. Collect any paperwork: surveys, repair certificates, guarantees, building control records.
3. Before you offer or remortgage, check what your lender (or a broker) will accept.
4. Get a survey from someone experienced with that type. You can ask for a quote here.