Discover our services

Attic conversions - Extension and veranda - Wine cellar.

Attics layout.

How to give a second life to a house that became too small?

Create your living rooms under roofs and get better insulation!

Harnois processes bring you turnkey solutions for you to expand your home and create new spaces in harmony with your personality and your budget. Carried out by qualified workers trained in the latest techniques. Layouts are made in accordance with the standards of the French DTU and specifications in agreement with SOCOTEC quality control, validated by each concessionaire internally to ensure excellence.

> Read more > View the catalog special "attic" in PDF format

Roof elevations

A vantage point to better see the big picture!

How to give a second life to a house that became too small ? Here you will find all the solutions to increase the habitable surface without encroaching on your garden.

When space is insufficient and you can’t push the walls or the roof is too flat, the one thing left to do is to elevate it to gain space!

Elevation is a surprising expansion solution, but feasible, provided you call in professionals.

Several solutions are possible when the roof is too flat: the slope change or elevation of walls.

> View the catalog special "Raising roof" in PDF format

Extensions - Verandas

The comforts of home, the pleasure of the garden: our "turnkey" solutions.

Whether originally motivated by a simple need of habitable surface or the joy and pleasure to bring the light into the heart of your home, light extension will not disappoint you.

> View the catalog special "bright extensions" in PDF format

Wine cellar

A real cellar for homes that do not have one, regardless of the floor of the house and the terrain.

Harnois filed in 1978 a patent for a method of cellar, ingenious and simple. Self-supporting, without foundations ...

This unique technical and commercial experience has enabled the development and installation of over 10,000 wineries.

Practical, efficient and compact: the rounds.

They have the largest storage capacity per cubic meter. They are suitable for storing wine, canned food or valuables and come in 5 sizes.

Large, friendly, rewarding: the ovals.

A more significant investment, they offer the best of investments by their storage capacity, the added value to your house and its space.

> View the catalog special "caves" in PDF format

Isolation

Until the early 2000s, regulations did not demand insulation. The result is that the average house consumes 250 kilowatts / m² / year that is to say, three to five times more than the current buildings.

Redoing the roof insulation and replacing windows with double glazing will reduce by 40 to 50% the loss of energy and heating bills.

Isolating the attic is a benefit to all the inhabitants of a house.

We also gain in comfort by eliminating drafts in winter and by keeping your home cooler in the summer.

The Grenelle de L’Environnement confirmed this priority by increasing financial aids for this work:

insulation tax credits, windows replacement... are available depending on your situation.

In addition to isolating the attic, wall insulation is also recommended. In order to avoid losing interior surface and redo its decoration, it is better to make a wall insulation from the outside, for example during a restoration.

When we rearrange the layout of your attic, we take great care of its insulation.

In addition, we also work to insulate the parts of the attic the can not be transformed into habitable space, usually at floor level.

> View the catalog special "isolation" in PDF format

A solution whatever your project is

You want to realize your project? We offer a free quote.