Modular extensions in Glasgow

Which Glasgow houses suit it

The inter-war bungalows and semis of Knightswood, King's Park, Giffnock and Bishopbriggs are the easy cases. They have a drive or a gap at the side, a back garden a crane can reach from the road, and a rear wall with few surprises. A single module or a set of panels can be in place in a day or two.

Tenement flats are a different matter. So are four-in-a-block cottage flats, which look like semis and are legally flats. Neither has permitted development rights for an extension, the ground at the back is often shared, and every owner with a share in it has a say. A ground-floor extension can be done, but it starts with the title deeds and a planning application, not with a factory.

Sandstone villas and terraces in the West End, Pollokshields and Dennistoun mostly sit in conservation areas. Expect a planning application and a design that the council's conservation staff will look at closely.

Which council you deal with

The city boundary is tighter than most people think. Bearsden, Milngavie and Bishopbriggs are East Dunbartonshire. Newton Mearns, Giffnock and Clarkston are East Renfrewshire. Paisley is Renfrewshire, Rutherglen and Cambuslang are South Lanarkshire. Each council is its own planning authority and its own building standards verifier, so your application goes to the council you pay council tax to.

The national rules are the same in all of them: the permitted development limits decide whether you need planning permission, and every extension needs a building warrant.

Ground, weather and access

Much of Glasgow and Lanarkshire lies over old coal workings. A mining report on the address costs little and tells the engineer whether shallow workings or a recorded mine entry affect the foundations. Get it before the foundation design is fixed, because a module needs its base built to tight tolerances.

The west gets more wind-driven rain than the east. Ask what cladding and membranes are proposed for a wall that faces south-west, and how the joint between the old house and the new room is sealed.

For the lift itself, a crane standing on the road needs the council's roads department to agree, and on a bus route or a street with parking on both sides that takes a few weeks to arrange. Panels carried through a side passage avoid the crane altogether.

What it costs in Glasgow

We have found no reliable published figures for Glasgow alone, so we use national ones. Fitted with VAT, finished modules typically run from £2,100 up to £3,300 per square metre, which puts a 20 m² room at roughly £42,000 to £66,000. Panel systems usually come in lower. Central-belt sites are close to most of the firms that build this way, so delivery adds little. Try the cost calculator with your own floor area.