Thermal insulation in Delémont

Looking for a company to carry out thermal insulation in Delémont usually starts from a simple observation: the home cools down quickly in winter and the heating runs a lot. In the capital of the canton of Jura, between the old town, the castle and the districts stretching into the valley, buildings date from very different periods, and insulation work in Delémont is not the same from one building to the next.

This page explains what this work covers, what the location changes, which permits and approvals to check and how to compare quotes.

Common insulation work in Delémont buildings

One trade, several possible jobs. Depending on the building, thermal insulation may cover:

• the roof and loft: often the first option, because heat escapes upwards; the loft floor or the rafters are insulated;
• the façades, from the outside or from the inside;
• floors and cellars: insulating the cellar ceiling or the ground-bearing floor reduces the feeling of a cold floor;
• thermal bridges: balconies, slabs, window surrounds, junctions between walls and roof, where heat escapes and damp can take hold;
• window replacement, which complements wall insulation rather than replacing it.

In Delémont, a villa in a residential district, an older apartment block near the centre and a building in the old town call for different solutions. In the first case, the owner alone decides the strategy; in the second, the co-owners or the landlord decide; in the third, the character of the building weighs on every choice.

Delémont, the Birse and Sorne valley: what the climate changes

Delémont lies in the Birse and Sorne valley. The canton of Jura has cold, snowy winters, with the Franches-Montagnes at altitude, while the Delémont valley and the Ajoie are milder. Delémont therefore does not have a highland climate, but winter is still harsh enough for the building envelope to really matter.

In practical terms:

• the loft and roof are exposed to the cold and, in snowy weather, to temperature differences that make an insulation defect visible: areas where snow melts faster, condensation under the roof covering;
• north-facing walls or walls exposed to valley draughts stay cold; this is where thermal bridges and mould appear first;
• cellars and lower floors, in contact with the ground, benefit from treatment to avoid a cold ground-floor surface.

A professional will look at the orientation, the exposure and the condition of the roof covering before proposing a system. There is no single solution: good insulation must also take ventilation into account, otherwise the damp problem is simply moved rather than solved.

Older buildings and the old town of Delémont

The old town of Delémont, with its castle, is one of the old towns cited in the cantonal rules, alongside Porrentruy and Saint-Ursanne. That does not in itself say what is allowed or forbidden for a particular building, but it calls for caution: before considering external insulation in this area, you need to ask the municipality.

In an older building, several habits are worth adopting:

• Do not trap damp. Old walls, often thick masonry, behave differently from a recent wall. A badly chosen material can trap water and cause damage.
• Favour what preserves the appearance. Roof, loft, floors and cellars can often be insulated without touching the visible façade, with a good balance between benefit and constraints.
• Consider internal insulation when the façade cannot be altered. It does, however, slightly reduce room sizes and requires particular care at the junctions.
• Treat windows with the same attention. Replacing windows in a sensitive building may also require approval, depending on the municipality and the building.

Permits and approvals to check before the work

External insulation changes the façade: a permit may be needed, depending on the municipality and the building. In the canton of Jura, the building permit is issued by the municipality or by the canton depending on the scale of the project. The municipality of Delémont is the right first point of contact: it will say whether an application is required and to whom it should be sent.

For energy matters, the canton has a cantonal energy section and a cantonal grant programme. The Buildings Programme (Programme Bâtiments) can also support some work depending on the canton. Conditions, amounts and deadlines change: ask the competent cantonal department before ordering the work, because a grant is in principle applied for beforehand.

Other approvals not to forget:

• House owner: you decide, but municipal permission still needs to be checked for anything that changes the exterior.
• Co-ownership: the façade, roof and windows are generally common parts; a decision of the owners’ meeting is required.
• Tenant: the landlord’s written consent is essential, and it is for the landlord to start work on the building envelope.

The CECB for setting priorities

The CECB, the cantonal energy certificate for buildings, gives a picture of the building’s energy condition and suggests renovation measures. For an older Delémont building where you do not know where the heat is escaping, it is a good starting point: it avoids investing in windows when the roof is the weak point, or the reverse. It can also serve as a basis for grant applications, depending on the conditions in force.

Preparing your request and comparing quotes

The more precise the description, the more comparable the quotes. Prepare:

• the type of building (villa, apartment block, old town), its approximate age and its use;
• the parts concerned: roof, loft, façades, cellars, windows;
• the heating system and the symptoms observed: cold walls, draughts, condensation, mould;
• photos of the roof, the façades, the loft and the cellar, and the CECB if you have one;
• your situation: owner, co-owner or tenant with the landlord’s consent.

A serious quote details:

• the areas treated and the materials, with their thickness;
• preparation of the substrates, scaffolding and waste removal;
• the treatment of special details: thermal bridges, junctions, surrounds;
• the finishes (render, cladding, plaster);
• what is excluded, and which formalities are or are not handled.

The cost varies with the surface area, the nature of the substrate, access to the site, the choice between inside and outside, the finishes and the extent of ancillary work. Compare quotes item by item rather than on the total alone, and check that each one answers the same request.

When your description is ready, you can request a quote: your request is passed on to craftspeople and companies in the region, who will contact you to prepare a free, no-obligation quote.

Useful pages on insulation in Delémont

• The trade in general: thermal insulation
• Work in the town: work in Delémont
• The cantonal context: canton of Jura
• In the same municipality: air conditioning in Delémont, electrician in Delémont, interior painting in Delémont