Rooflight and skylight installation in Boxted

Farmhouses

These frequently combine several building periods in one roof, extended and altered repeatedly over centuries. Pitches vary within a single property, coverings change from one section to the next, and the timber ranges from historic hand cut rafters to twentieth century repairs.

Two practical consequences follow. Every dimension is measured off the building at the position the unit will actually occupy, because a rafter spacing measured in one bay may be different in the next. And where historic timber is part of a listing, an opening is positioned to avoid it rather than cut through it, which means the survey establishes where a rooflight can go before anybody discusses what it should be.

These buildings also move seasonally. Fixing has to allow for it rather than clamp a rigid modern unit into a frame that flexes, which is how a seal gets stressed and fails early.

Converted agricultural buildings

Common across the parish and worth treating as their own category.

The first question is what the roof is actually made of. Some are historic timber, some are twentieth century lightweight trusses, and some are steel framed. The answer decides whether a heavy unit such as a lantern needs structural work, and it is not something to assume from the appearance of the building.

The second question is what the original permission said. Barn and agricultural conversions are frequently granted with conditions about rooflights, or with permitted development rights removed entirely by condition, and those conditions run with the property regardless of who owns it now. Reading the permission before assuming permitted development applies saves a wasted application or, worse, an enforcement problem.

Where a conversion already has rooflights built into the design, adding more is a different proposition from cutting the first opening into an unaltered roof, and it is usually an easier case to make.

Consent

Listed building consent is required for a rooflight on a listed building, always, on any slope, whether or not anybody can see it. There is no rear elevation exception and no small works threshold. The parish has a good number of listed farmhouses and cottages, so this is not an unusual situation here.

Where a property is unlisted and outside any conservation designation, which describes much of the twentieth century housing, permitted development normally applies: no more than 150mm projection beyond the plane of the roof and not above the highest part of it.

Exposure on open ground

Properties standing in fields take considerably more wind than a house in a village street, and driving rain matters more for a roof window than total rainfall does, because wind driven water is pushed under a covering rather than running down it.

That puts almost the whole weathering burden on the underlay collar and the flashing kit rather than on gravity. Specify the kit correctly for the covering and generously lapped rather than accepting a universal one, and use stainless fixings rather than plated, which cost very little more and do not bleed rust down an exposed roof.

Coverings

Handmade clay plain tile and peg tile on the older buildings, slate on some nineteenth century property, pantile on a number of the agricultural buildings, and concrete interlocking tile across the twentieth century housing.

Pantiles are worth calling out because they need their own deep flashing profile and are unforgiving of a universal kit. Handmade clay is the most demanding of all: a proportion breaks on removal whatever care is taken, and the usual answer is to take sound tiles from a hidden slope and place the replacements there.

Access and coverage

Excellent on site, with space around almost every property to stand a tower or erect scaffold on private land, and no highway licences to arrange. The practical constraint is more often the route for a delivery vehicle carrying a large unit down a narrow lane, which is worth establishing at survey rather than on the day.

We plan Boxted work as full days rather than short visits. Access is a fixed cost shared across everything done on the same visit, so mention everything that needs doing at the enquiry stage.

Why we will not fix a price from photographs alone

On an older rural building there are too many things a photograph does not show. Whether the timber around an existing opening is sound. Whether there is underlay. Whether the rafter spacing at the intended position matches what it is elsewhere on the slope. Whether the roof has been recovered and what was done at the time.

A fixed price given without seeing those is a guess with a margin built in to cover the guessing, and it either costs you money you did not need to spend or it changes on the day. Neither is a good outcome, so we survey.

What is found, and how we handle it

On a building of some age, decayed rafter ends, crumbling battens and absent underlay are all realistic rather than remote. We name a contingency in the quotation with an indication of cost, so the possibility is stated in advance rather than presented as an invoice afterwards.

Where we find something on strip out, work stops and we tell you what it means before continuing. Where a historic timber turns out to be significant on a listed building, we consult the conservation officer before anything is cut. That is slower and it is the correct sequence.

Guarantee

Ten years on our workmanship, alongside the manufacturer’s warranty on the product. Most rooflight problems are installation problems, which is why the first matters more, and where a unit fails under the manufacturer’s warranty on a job we did, we handle that claim ourselves.