NHBC Guidelines for Wooden Windows

New Build Inspections


New Member

We have been in our new build house for nearly two years and tomorrow we have the Persimmon Customer Care Manager coming out to see us to talk through our queries we have with our wooden windows.

The main problem is that the wood knots are starting to come through the paint I would have thought that the knots would have been sufficiently treated so they wouldn't do this. Is there any technical NHBC standard we can quote? The paint would appear to have been applied at the factory and looks as though it has been sparyed or dipped. It certainly does not appear to be gloss. We are concerned that if they treat the knots, the windows are going to patchy with miss matched paint. Can we request that they repaint all of the affected windows?

We have alo noticed that the paint on one of the barge boards on one of the dormer windows has started to peel. Surley, you don't expect to repaint this within two years of moving in? Is this something we should also raise with Persimmon before the two year warranty expires?

Thanks in advance.


New Member
All your assumptions are correct.

Paint is covered in NHBC Standards Chapter 8.5

Knots in timber should be treated. If they have to be retreated on site then the new surface application should match adjoining surfaces, which means the windows will probably have to be redecorated complete. It sounds from your description as if the factory applied finish is satin rather than gloss and is an acceptable finish.

The bargeboard is probably the result of painting under/after adverse weather conditions and should be redecorated as a snag.


New Member
Thanks willyj. The Customer Care Manager has a agreed to repaint the barge board and will come back to us re the windows.