Build without nasty surprises

Why investigate the soil before building

Foundations transfer the entire weight of the building to the ground. If the soil gives way, even slightly, the whole structure suffers. And soil changes from one plot to the next, sometimes even within the same plot.

Difficult soils are common in Madagascar

• Former rice fields and backfilled lowlands, very common on the Antananarivo plain: recent fill often sits on soft, compressible soils.
• Groundwater close to the surface in the rainy season.
• Water-sensitive clays that swell and shrink with the seasons.
• Sloping ground, lavaka (erosion gully) areas and heterogeneous lateritic soils.

What happens when you build without knowing

Poorly understood soil causes uneven settlement: cracks in walls, tiles coming loose, doors and windows that stick. In serious cases, the foundations must be reworked under a building that already exists, which costs far more than the study that would have prevented it.

What a soil investigation includes

1. Site visit and enquiry: history of the plot, fill, water, slope, neighbouring buildings.
2. Field testing: boreholes, dynamic penetrometer, sampling.
3. Laboratory testing: particle size analysis, Atterberg limits, water content, depending on the soil encountered.
4. Report and recommendations: type and depth of foundations, bearing capacity, precautions against water.

We follow the sequence of geotechnical assignments in standard NF P 94-500, from the preliminary study (G1) to the design study (G2), and design foundations to Eurocode 7.

When should it be done?

Ideally before buying the plot, to know what it is really worth. At the latest before the structural drawings, since the choice of foundations depends on it. It costs only a small fraction of a construction budget.

Buying land: the checks to make before signing

A poorly checked plot can block a project for years: disputes, contested boundaries, construction prohibited. Here are the points to check before you pay.

1. Land status

A plot is either titled, with a land title held by State services (Land Registry and Topography), or untitled private property, evidenced by a land certificate issued by the municipal land office. For titled land, ask for a recent certificate of legal status: it shows the registered owner and any charges, mortgages or objections.

2. The seller

Check that the seller is the registered owner, or holds a valid power of attorney. For land that is part of an inheritance, the agreement of all heirs is essential.

3. Boundaries and area

Compare the plan on the title or certificate with what is on the ground: boundary markers, fences, area. A topographic survey removes any doubt and is then used for the design.

4. Planning rules

Can the plot be built on? For what use, what height, what footprint? Is there a required setback, an easement, a future road crossing the plot? These rules decide what you will be able to build.

5. Site risks

Flood zone, recent fill, steep slope, lavaka nearby: visit during the rainy season if possible, and have at least a preliminary soil investigation carried out.

6. Access and utilities

The plot must have legal access, not just a passage tolerated by a neighbour. Find out how far it is from the water and electricity networks, and how wastewater will be drained.

7. Signing

• Have the deed of sale drawn up by a professional, preferably a notary.
• Never pay in full before completing these checks, and keep a receipt for every payment.
• Have the transfer registered in your name with the relevant office.

The building permit, step by step

Since Law No. 2015-052 on urban planning and housing, a building permit is mandatory before any construction. It is issued by the municipality. Here is the usual process.

1. Check the plot. Land status in order and planning rules known. If in doubt, a planning certificate can be requested from the municipality.
2. Have the project designed. Plans, elevations, sections and structural calculations that comply with planning rules and the national building standard. An architect is involved where regulations require one.
3. Prepare the application. Generally: the application form, the land document, a location plan, a site plan, the building drawings and technical notes. The exact list and fees depend on the municipality.
4. Submit and follow the review. The municipality's technical services examine the application; other services may be consulted depending on the project.
5. Receive and display the permit. The permit is displayed on site, visible from the public road.
6. Build according to the drawings. The municipality may inspect the site; any significant change must be authorised.
7. Declare completion. Depending on the municipality, a compliance inspection may take place.

Costly mistakes

• Starting work before obtaining the permit: site shut down, fines, even demolition.
• Submitting drawings that do not comply with planning rules: refusal and lost time.
• Building on disputed land: a permit does not protect you from a land dispute.

Why it takes time, and how to avoid delays

Obtaining a permit can involve many steps and several months. A complete, compliant application from the outset is the best way to save time. That is also why our CEO, together with urban professionals, advocates a simplified permit based on pre-approved house designs.

Building for a changing climate

Stronger cyclones, violent rain, heat, drought in the South: a building must be designed for today's and tomorrow's climate. Building to standard costs only about 15% more, according to Madagascar's emergency prevention and management unit (CPGU).

Withstanding wind

• Simple, compact shapes and a roof pitch suited to wind.
• Roof structure and covering firmly anchored to the building, roofing sheets properly fixed.
• Horizontal and vertical ring beams that hold the walls together.
• Openings protected during cyclones.

Protecting against water

• Build outside flood zones, or raise the floor.
• Drain around the building and evacuate roof water properly.
• Collect rainwater for everyday uses.

Staying cool without air conditioning

• Orient the building according to the sun and prevailing winds.
• Encourage cross-ventilation.
• Insulate the roof, provide overhangs and sun shading, choose light colours.

Materials that last

Well-proportioned, properly placed concrete, reinforcement with adequate cover, especially near the sea, and proven local materials such as brick and stone, used correctly.

Depending less on the grid

Solar panels with batteries and efficient lighting: power stays available during outages and bills go down.