What the job costs in Finchley
Pair of windows
Two roof windows into a loft room, flashings and linings
Three or four windows
Bigger loft rooms or stairwells
Balcony or combination
Balcony-style or stacked window combinations
Guide ranges for supply & fit. Your price is fixed in a written quote after we have seen photos or surveyed. Scaffold, access towers or a crane are priced separately if the job needs them, and building control fees, where a job needs them, are shown as their own line.
Is your address covered?
Distance is rarely the deciding factor. A roof in Golders Green, 2 miles from Finchley, gets the same survey, the same written quote and the same fitting process as one in N3, N12 and N2. What changes the price is the job itself: size of unit, roof type, access and lifting. Friern Barnet, around 2 miles out, is treated the same way.
What we check on a supplied unit
Which works out better, buying your own or letting us supply? It depends on what you value. Buying your own gives you control of the product and what you pay for it. Letting us supply puts the whole job, unit and fitting, under one written quote. On a customer-supplied unit we still measure it against the opening, look at the upstand, and inspect the condition it arrived in. Warranty on the product sits with whoever sold it, while the fitting carries our own guarantee.
Included in the work
- Insulation collars fitted so the room's insulation meets each frame
- Tiles or slates cut and refitted, with the roof left weathertight
- Underlay dressed and taped around every frame
- Energy performance in a loft — We check every window meets the energy limit for roof windows in existing homes.
- Fitting stage and weather — We plan when the windows go in around the rest of the conversion.
How a fitting day runs
Where a job takes one to two days, the split is usually structural work first and finishing second. Early on, the fitters cut or prepare the opening, trim where needed and prepare the upstand or flashing. Then a loft roof window is lifted in, fixed and made weathertight so the roof is sound before anyone moves inside. Plasterboard, trim and filler for the reveal come after. Each evening the work area is swept, and at the end the glass is cleaned and the team talks you through what was done.
Planning and building rules in England
England's rules in short: permitted development usually covers a rooflight on a house roof provided it doesn't stick out more than 0.15 m or rise above the ridge, though a listed building always needs consent and some streets have Article 4 directions. Building regulations apply to new openings, and replacements go through building control; as we are not registered with a competent person scheme, we use a building notice and show the fee on the quote. The energy limit for rooflights in existing homes is 2.2 W/m²K, and the 2026 Approved Document L, in force from 24 March 2027, keeps that figure.
What to send for a quick quote
A fast quote needs five things: a photo of the roof from outside, one from the room below, rough sizes of the opening or the space, the roof covering (felt, single-ply, fibreglass, tiles, slate or metal), and a note on access. If you have already bought the unit, add the product link or spec sheet. And give us the postcode, N3 or a neighbouring district.
Common questions in Finchley
Can you fit the loft roof window I bought online?
Yes, fit-only is one of our core services. Send the product link or spec, photos of the roof and rough sizes, and we can usually price it from those. Before fitting we check the delivery for damage, which should be reported to the seller, plus the size against the opening, the flashing kit and the roof pitch. The product warranty stays with the maker or seller, and our guarantee covers the fitting.
What if my roof opening is the wrong size for the loft roof window?
We find out before the fitting day, not on it. If the opening is slightly out, it can usually be adjusted by trimming or by packing out the upstand. If it is a long way off, the choice is between altering the opening and changing the unit. Bear in mind that rooflights are often sold by builder's opening size rather than external size, so check which one your measurement refers to.
What is included in the price?
The written quote lists it line by line. Typically that covers fitting labour, fixings, sealants, membrane or flashing materials, any upstand work, internal finishing if agreed, and taking away the waste. For supply and fit, the unit itself is included too. Scaffold, lifting gear and any third-party fees, where needed, are shown separately so you can see what each part of the job costs.
Planning a loft roof window in Finchley? Tell us about the roof and we will come back with a clear price in writing.

