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Gardens and buildings

 Often when adapting or re-planning a garden by adding new trees or shrubs, we are so focused in on the garden that we do not think how this may impact on the performance and comfort within the building. An example would be the planting of a tree too close to the house. As the tree grows, its roots expand and may cause damage to the foundations, resulting in extensive structural problems that are very expensive to fix. 

A  tree that grows too big also may start blocking out the sun, making the room behind cold and gloomy. It is always worth checking how tall the tree will grow, from a good gardening or tree book, or by browsing the net. Your plant nursery may also be able to advise on the final size of the tree. As a rule of thumb, plant the tree the same distance from the building as its height - This should allow sufficient sun to come in during winter. It is also worth looking into deciduous trees for planting nearer the house, as these will block the sun in summer, keeping the house cool, yet let the sun in to the rooms in winter. This can save you a fortune in electricity to heat and cool your home!

The roots of a tree or shrub will grow to approximately the same diameter as the crown of the plant, so if you can find out the anticipated spread of the tree, this will ensure that you do not have problems with the foundations. As a rule of thumb, most garden trees grow to a maximum diameter of 10m, so plant them with the trunk at least 5m from the nearest walls.

Some trees have rampant root systems, which can infiltrate the drains, entering through hairline cracks or joints in the pipework. This can cause severe blockages and even extensive damage to the pipes. You may have the plans of your home, which should show the position of the sewer lines, but if not, you can usually determine this if you know where the sewer connection point is on the street edge (there may be a manhole cover, or it may be next to the water meter). Imagine a line from this point to the nearest bathroom or the kitchen and avoid planting any trees within 5m of this line.

It is also tempting to have flower-beds hard up against the walls - if you have planted water-loving plants, the soil will hold moisture most of the time, potentially causing rising damp. If your soil is clay, this can also cause foundation settlement problems as the clay expands and contracts depending on the varying moisture content. Clay soil is usually red or light grey, and forms a ball in your hand when slightly wet.

Flower-bed hard up against a wall, potentially giving damp problems

Rather have a strip of paving or gravel next to the house walls, and keep the flower-beds at a distance of at least 50cm. You can arrange some pots with flowers on the paving if you want to soften the line of the wall where it meets the ground, but be sure to have drip trays under each pot to prevent damp. 

A pot plant with a drip-tray close to a wall

Houses covered in ivy or Virginia Creeper look very romantic, but these plants can damage the walls they are growing on. It is possible to have a "green wall", but this requires very high quality waterproofing of the entire wall and the inclusion of a root barrier before you start planting.

Grass is not such a problem, as it does not stay saturated, so you can plant close to the building. 

Grass can be planted close to a building

Likewise, you can plant succulents and other plants that need very little water right up against the walls. I am a fan of succulents, as they require so little maintenance and look good all year round. They also help to purify the air - spekboom absorbs the same amount of carbon dioxide as a tree of the same coverage.

In the end, a good landscape design complements the building both aesthetically and practically.

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