Matching a conservatory roof to the house roof

People usually start with colour. A sample held against the house roof looks close, the order goes in, and then the new roof looks flat and bright for the first year. Colour is only one of five things the eye reads: colour, texture, the size of each tile, how the courses sit, and the finish at the edges.

Texture matters because an old roof has a face. Clay and slate pick up lichen, dust and weathering that a new tile does not have on day one. Size matters because a plain tile and a larger interlocking tile make different shadow lines even when the colour is identical. The courses are the horizontal rows, and their spacing sets the rhythm of the whole slope.

Edges are the part that gives a poor match away. Three terms help here: the ridge crowns the roof, a hip runs down where two slopes join, and the verge finishes the gable end. If the conservatory has a plastic trim where the house has a tile-and-mortar verge, you will see it from the garden. Our guide to lightweight tiled conservatory roofs explains how those systems are built; this page is about how they look.

If the house is slated, the conservatory is a simpler match than if it is stone. Natural slate varies by origin, and Welsh and Spanish slate differ in tone and surface even when both are grey. Ask the supplier for loose slates and lay them against the house roof outdoors, not under a showroom lamp.

Stone is stricter. The guidance on stone slate roofing that Cotswold District Council published in 2000 reproduces English Heritage policy on replacements. Follow the originals on rock type, shade, grain, size and thickness, it says, and never let limestone stand in for sandstone or the reverse. The same text rejects fibre-resin slate, concrete tile and reconstituted stone on historic buildings. That is guidance written for old buildings, but the logic carries over to a conservatory on a stone house: a grey imitation will look wrong beside oolitic limestone.

Real stone is heavy, about 1,000 kg for every 10 m² of roof in the same guidance, and most conservatory frames were never designed for it. So on a stone house the usual compromise is a lightweight roof whose finish is chosen to sit quietly beside the stone, rather than a stone roof the frame cannot carry. Our page on whether the frame can take a heavier roof covers that check.

Even a perfect match on paper will stand out for a while. New clay is brighter, new concrete tile has a sheen from its coating, and new slate is darker and cleaner than a roof that has had decades of weather. Over the first seasons rain, lichen and sun soften the difference.

You can help it along by choosing a slightly weathered tone when the house roof is old, and by looking at the house roof in the same light as the samples. Reclaimed tiles are another route when a conservatory roof is small, because they already carry the patina. We would not suggest them where the supply is uncertain; a small roof still needs enough sound tiles of one type, and running short halfway through is a bigger problem than a mild mismatch.

It is also worth looking at the house roof itself. Roofs that have been repaired over the years often contain tiles from several batches, and what you are matching to may be an average of the whole slope rather than one clean tile. We photograph the roof during the survey so the choice is made from your actual slope, not a catalogue picture.

A solid conservatory roof is a small pitched roof, so it needs the same junctions as any other. Lead flashing, a metal strip stepped into the wall joints, closes the joint between roof and house. Done well, the flashing follows the line of the house brickwork or stonework and looks as though it has always been there. Done carelessly, it is a bright strip across the wall.

The same goes for the ridge and the eaves. A ridge in a matching colour, fixed mechanically and finished neatly where it meets the house, reads as part of the roof. A dry-fix ridge, which clips on rather than being bedded in mortar, comes in colours and can be chosen to match. Gutters and fascia boards should match the colour and profile on the house as well, because the eye follows the roofline.

Rooflights set into a conservatory roof can also upset the match if they stand proud. Keep them low and in line with the slope, or leave them out when the house roof has none.

Stroud District has 41 conservation areas, and a listed house has legal protection, so the choice of roofing material can matter for more than looks. A conservatory that is attached to a listed building may need consent, and in a conservation area you should ask the planning team whether anything applies to the roof covering before you order. The council page on Article 4 Directions, which remove some permitted development rights in five of its conservation areas, does not say whether roofs are affected, so ask the team.

Making the roof solid is a material alteration, which brings in a Building Regulations application. Planning Portal guidance adds that a roof change which reshapes the structure or look of the building in a big way can bring planning permission into play. Matching helps on both counts: a roof that looks like the house is easier to defend as a modest change. Read our overview of replacing a conservatory with an extension if the project is growing, and the page on orangery roof lanterns if a glazed centre is part of the plan.

We explain which consents apply, handle the Building Regulations notification, and give you a written quote for the whole job after the survey. The finished roof carries a written guarantee on our workmanship, for ten years. See the conservatory roof replacement page for the full picture.