Building a House: From Site Preparation and Foundations to the Roof

A house starts before the walls go up

A reliable build depends on many connected decisions: where the house sits on the plot, how excavation is organised, how the foundations suit the site and design, how loads pass through walls and floors, how structures are protected from water, and where services need to pass through the building. A decision made early can create problems much later, when correcting it may require demolition or rework.

What we cover in our construction guides

• site preparation, setting out, excavation, trenches and foundation pits;
• foundations, sub-bases, ground floors, waterproofing and protection of below-ground structures;
• load-bearing and non-load-bearing walls, columns, beams, lintels and structural frames;
• upper floors, stairs and structural connections between levels;
• roof structures, roofing, drainage and junction details;
• window, door and garage-door openings and preparation for installation;
• the sequence of construction work and the dependencies between different stages;
• planning penetrations and routes for electrical, water, drainage, ventilation and other building services.

A typical construction sequence

On a real project, some stages may overlap and the exact order depends on the construction system, design and site organisation. The useful principle is not to copy one universal sequence blindly, but to identify which decisions must be made before the next layer or structure makes them difficult to change.

The site and ground affect everything built above them

Ground conditions, water, topography, the depth of below-ground construction, access for machinery and the position of utilities all influence excavation and structural choices. A foundation solution should therefore be considered in the context of the actual site rather than selected only because a similar system worked well on another house.

Foundations work as part of the whole building

A foundation is more than concrete beneath the walls. Its geometry, bearing conditions, reinforcement, joints, levels and moisture protection need to coordinate with the loads from the building and with surrounding work such as backfilling, ground floors, drainage, external paving and service entries. Decisions made here can be particularly expensive to correct after construction continues above.

Walls, floors and frames need to be considered together

Water finds weak details

Durability depends on more than strong materials. Rainwater needs a clear path away from the building, below-ground structures need suitable protection, and roof edges, window sills, terraces and other junctions need to manage water rather than trap it. Many defects begin not in the middle of a large surface but where two different elements meet.

Plan openings and service penetrations before concrete and masonry

Windows, doors, garage doors, ventilation ducts, drainage outlets, water supplies and electrical entries all need physical space in the structure. Coordinating them early helps avoid situations where a finished foundation, beam, wall or floor has to be cut or drilled in a place that was never intended for an opening.

How to use HomDera construction guides

• use the guides to understand the logic of a construction stage and prepare better questions for designers or contractors;
• before ordering work, check what needs to be completed first and what the next stage will require;
• take dimensions, loads and structural requirements from the documents for your own project rather than from someone else's example;
• when comparing construction methods, consider installation, compatibility with adjoining layers and future maintenance as well as material price;
• photograph hidden work and record useful dimensions before it is covered by later construction or finishes;
• use HomDera calculators as supporting planning tools and check the inputs against your own drawings, quantities and local requirements.

Common questions about building a house

Where should I start when planning a new house?

Start with the project inputs rather than buying blocks or concrete: the plot, local constraints, the household's needs, the intended floor area, budget and design approach. Before excavation begins, it is useful to understand the building position, main levels, structural concept and where the main utilities will enter.

Can the layout be changed once construction has started?

It depends on what is being changed. Moving a lightweight partition is very different from altering a load-bearing wall, column, floor opening or staircase. The more construction is already complete, the more important it becomes to check structural effects, services, room geometry and the approved design before making a change.

What should be checked before concrete is poured?

Before a pour, check geometry, levels, formwork, project-specified reinforcement, embedded items, openings and service penetrations. Many of these details become harder and more expensive to correct once the concrete has cured, so verification before the pour is especially valuable.

When should electrical, plumbing and ventilation routes be planned?

The main routes and penetrations through foundations, walls and floors are best coordinated before those structures are built. Detailed distribution can be installed later, but the positions of risers, incoming services, larger ducts and major equipment are easier to accommodate when they are known early.

Why is it useful to photograph hidden construction work?

After backfilling, concreting, plastering or closing a wall or ceiling, parts of the structure and services become invisible. Photos with useful reference dimensions can later help locate pipes, cables, embedded items and joints during repairs, drilling or future alterations.