How to Build an Open Terrace Attached to Your House

Today an attached terrace gives the opportunity to enlarge the living area and create extra space for full‑time leisure. Closed, glazed extensions also reduce the building’s heat loss. Building a terrace yourself does not require huge expenses and can be done with DIY skills. The most important step before starting work is to develop a proper project plan and select suitable materials.

Types

By construction method, terraces are divided into open and closed with glazing. The open type is ideal for warm‑season use, while closed verandas are suitable for year‑round use. Modern terraces can be combined, i.e., half‑glazed.
A veranda can also be pass‑through, meaning you must walk through it to reach the house interior. Such an addition is usually placed on the side of the front or rear entrance. A non‑pass‑through veranda does not allow direct exit to the street.
A terrace may wrap around one or more sides of the house. When it occupies space along two adjacent walls, it is called a corner‑type extension. More often it covers only part of a single wall. Shapes vary: the traditional rectangle is most common, while semicircles and hexagons are rarer because they are more complex to build.

Material Selection

In many regions, builders usually choose wood for terrace construction. It is cheaper and much easier to work with. In areas where timber is expensive, structural elements are made of metal, and the cladding can be selected at will, for example polycarbonate or glass.
Veranda walls can be built from limestone, brick, concrete block, or natural stone. The finished structure may be left untreated or finished later, depending on the overall façade style.
When you prefer not to treat wood, the frame is best assembled from metal, specifically profile pipe. This base readily accepts polycarbonate sheets or double‑glazed units. Despite its seemingly fragile appearance, the material is sufficiently strong and retains heat well.

Construction Stages

The builder must decide on the type of addition, its foundation, and the material for its construction. Before work begins, determine the veranda’s dimensions and its intended location. It is best to draw all measurements on a detailed plan showing pathways and other site features.

Construction proceeds in a clear sequence. If wood is the chosen material, follow this plan:

1. Mark the outline of the future addition with rope and stakes.
2. Within the marked perimeter, completely remove the fertile layer and turf. Skipping this step allows vegetation under the deck to rot and emit unpleasant odors.
3. Mark and plan the foundation. Usually the foundation is non‑continuous, “floating,” and the terrace floor is initially set five to ten centimeters lower than the main floor level. This ensures the addition, even when slightly raised, does not block the entrance doors.
4. Attach a support beam to the wall. The height of the foundation is cut off at its lower edge, after which construction begins. Cement is poured into the bottom of the pit prepared for the support. Once it reaches at least half of its strength, the pit bottom is backfilled with crushed stone, which must be thoroughly compacted.
5. Lay a waterproofing layer over the finished foundation. Then position and secure the vertical supports for the roof.
6. Perform the bracing of the supports. For this, a 100 × 150 mm timber beam is nailed around the terrace perimeter. It can be fastened between the posts or externally, but only before the floor decking is installed.
7. Ceiling beams are attached to the support beam and foundation. Their spacing matches the spacing of the posts or piles. The rafter system is assembled.
8. Install side railings for open extensions or walls for glazed ones. Finally, carry out exterior and interior finishing.

These steps represent a standard, typical instruction. To gain a fuller picture of terrace construction, the most problematic moments should be examined in more detail.

Foundation Organization

Linking the main house foundation with the new one is not recommended because the house has usually settled already. Rigidly attaching a new structure can cause problems unless the house stands on stable, non‑shifting ground. Moreover, terrace foundations are typically lightweight, so the bearing capacity of a column or pile foundation is usually sufficient.

How to Attach a Post?

After the concrete foundation gains partial strength, the frame of the addition can be built. At temperatures around twenty degrees Celsius, installation can start on the fifth‑sixth day after pouring the foundation. First, a waterproofing layer—such as double roofing felt coated with bitumen—is laid.

To quickly and conveniently secure the posts, special holders must be placed in the foundation during pouring. These are “P‑shaped” metal plates with a lower spindle that ensures a firm connection. To make the open terrace last as long as possible, the post ends are pre‑treated with antiseptic and fastened with nails or bolts to the plate. Following all recommendations, you can build the attached terrace yourself without any problems.