Energy renovation in the Bas-Rhin (67)
The Bas-Rhin has an immediately recognisable building heritage: Alsatian half-timbered houses, wine-growing villages with narrow streets, and large farmhouses out on the plain. Strasbourg adds its conservation areas and its reconstruction-era buildings, while the ring around the conurbation concentrates detached homes and small blocks of flats. The continental climate brings cold winters and hot summers, which puts summer comfort on the same footing as heating. On this older, tightly constrained building stock, ventilation is decisive. GRAM Énergie supports owners from the initial assessment through to the commissioning of the equipment.
Tip: have your energy performance certificate (DPE) and energy bills to hand for a more accurate estimate.
The Bas-Rhin building stock and its energy challenges
A half-timbered house consists of a timber frame infilled with cob or brick. This wall lets water vapour through and copes badly with vapour-tight insulation: an unsuitable lining causes condensation within the infill and attacks the timber. We therefore work with breathable materials, respecting continuity between the panels, the wall plates and the floors. Every visible façade is examined beforehand.
In the old centres and conservation areas of Strasbourg, as in the wine-growing villages, external insulation is rarely permitted. Projects then shift to the interior, the lofts and the floors, with rigorous treatment of thermal bridges. The joinery calls for particular care, as its design is often regulated. Reconstruction-era buildings, by contrast, offer more technical latitude.
The climate of the Bas-Rhin combines cold winters with hot summers, sometimes muggy out on the plain. A successful renovation therefore also protects against overheating: retained thermal mass, solar shading, night-time ventilation. This twin requirement runs through all energy renovation in Grand Est, but it is particularly marked here, where the older building stock is both constrained and sensitive to moisture.
Our services in the 67
Global energy renovation
Global energy renovation addresses the building envelope, the heating, the hot water and the ventilation together. On a half-timbered house this coherence is essential: every intervention alters the moisture balance of the wall. We draw up a prioritised scenario, which can be carried out in one go or in stages, while preserving the way the building was constructed and the compatibility of the materials with one another.
Heat pump
An air-to-water heat pump generally connects to the existing circuit, once the emitters and the level of insulation have been checked. In the Bas-Rhin, cold winters call for sizing based on an on-site survey and close attention to the flow temperature. In an old town centre, the position of the outdoor unit has to work around narrow courtyards, close neighbours and local rules.
Insulation
Insulation almost always starts with the lofts, which are very accessible in Alsatian houses with their large roofs. Ground floors and walls follow. On half-timbering or a protected façade, a breathable internal solution is the only realistic option. The choice of insulation takes account of the substrate, its moisture content and its ability to release water vapour to the outside.
Thermodynamic water heater
A thermodynamic water heater produces domestic hot water by recovering heat from the indoor or outdoor air. The cellars and utility rooms that are common in Alsatian buildings suit it well. We check the volume of the room, the scope for ducting and the distance from the bedrooms, so as to avoid any noise nuisance once the appliance is in service.
Energy audit
An energy audit describes the actual condition of the home and proposes costed, prioritised scenarios. On an older, constrained building it avoids expensive mistakes: insulating a damp wall, choosing an incompatible material, neglecting the ventilation. It is also the reference document for a major project and for discussions with everyone involved.
Mechanical ventilation (VMC)
Ventilation is decisive on older buildings: without controlled air renewal, the moisture produced day to day settles in the walls and damages both the cob and the timber. We install humidity-controlled single-flow or heat-recovery double-flow VMC systems depending on the configuration and the level of airtightness achieved, taking care over the duct routing and the air inlets in the main rooms.
Smart thermostat
Controls make it possible to match the heating to actual use, room by room and according to when the home is occupied. In older houses with high thermal mass, well configured control avoids sudden swings and evens out the temperature. We set the system up with you after commissioning and explain the heating curves, because a poorly configured device loses its benefit.
The towns we work in across the 67
We work throughout the Bas-Rhin, from the Strasbourg conurbation to the wine-growing villages and the market towns of the plain.
- Strasbourg: conservation areas, reconstruction-era buildings and blocks of flats, with strong heritage constraints on visible façades.
- Haguenau: an old centre and suburban districts, where the lofts and the joinery are often the first items to be tackled.
- Schiltigheim: a dense fabric of town houses and small blocks of flats, for which internal insulation remains the most realistic solution.
- Illkirch-Graffenstaden: detached homes and recent developments, with older heating systems frequently replaced by a heat pump.
- Lingolsheim: mixed housing on the plain, where summer comfort is becoming as important a criterion as winter performance.
- Saverne: older foothill buildings with thick masonry, calling for breathable insulation and suitable ventilation.
- Sélestat: a constrained historic centre and a more recent periphery, two renovation contexts that must be handled separately.
- Bischheim: semi-detached houses and post-war blocks, whose roofs and ground floors offer quick gains.
- Obernai: a wine-growing village with protected buildings, where the works concentrate on the interior, the lofts and the joinery.
- Hœnheim: detached homes and small blocks, with projects that often combine insulation, ventilation and a change of heat generator.
Grants and funding
Several schemes can fund part of the works: MaPrimeRénov’ (the French national home renovation grant), the certificats d’économies d’énergie (CEE, the French energy saving certificate scheme), the reduced rate of TVA (French VAT) and the éco-prêt à taux zéro (éco-PTZ, an interest-free renovation loan). Grants specific to blocks of flats also exist, as do schemes run by local authorities in the Bas-Rhin. The conditions depend on the home, the household’s income and the nature of the works. We put the applications together with you and point you towards the public service France Rénov’ for official information.
Grant applications are prepared before any works quotation is signed.
How a project runs with GRAM Énergie
An initial discussion, then a site visit
We survey the building, the equipment in service and how you actually use the home.
Thermal study or audit
We prioritise the works and compare several costed scenarios.
Step 3
Detailed quotation and preparation of the grant applications, with the list of supporting documents to gather.
Step 4
Carrying out the works, coordinating the trades and monitoring the site through to handover.
Step 5
Commissioning, adjustments and an explanation of how to use the system, then support in monitoring consumption.
Frequently asked questions
Can a half-timbered house be insulated?
Yes, but with breathable materials and continuous workmanship between the panels and the structure. Vapour-tight insulation applied over cob causes condensation and damages the timber. We check the condition of the infill and the renders before any decision is taken, and we adapt the ventilation at the same time.
What can be done if external insulation is refused?
This is common in the protected areas of the Bas-Rhin. The project then shifts to the interior, the lofts and the ground floors, with careful treatment of the thermal bridges at the junctions. The joinery is replaced in keeping with the original design where that design is governed by local rules.
How can you limit the heat in summer?
By retaining the thermal mass of the thick walls, insulating the roof properly and fitting solar shading to the exposed openings. Night-time ventilation completes the picture. On the plain, where summers are hot, this aspect is studied from the design stage of the project rather than added afterwards.
Is a heat pump suitable for older buildings?
Yes, if the building envelope has been addressed and the emitters can work at a moderate flow temperature. In a home that has remained poorly insulated, efficiency drops sharply during cold spells. We check these conditions with a full survey before proposing a model and an output.
Do you work across the whole département?
Yes, we work throughout the Bas-Rhin, from Strasbourg and its ring to the market towns of the plain and the wine-growing villages. A site visit is always carried out: it determines the survey, the sizing and the real feasibility of the works, particularly on façades subject to heritage rules.
Are you preparing a renovation in the Bas-Rhin? Tell us about your home and your objectives using our contact form: we will arrange a visit and build a works plan compatible with your building and the applicable rules.
Let’s talk about your project
Tell us about your home and your goals: we help you prioritise the works and identify the grants worth looking into.