The National House Building Council‘s guide to safeguarding homes
Planting trees near houses is a common mistake – but how close is too close? Many of us, including me, love to see a tree outside the window. However, some root systems can damage your home’s foundations.
Inexperienced gardeners often pick up the first plant they see with little regard to its eventual height or spread. The prime culprit is the Leylandii conifer, often seen towering over gardens. Most were planted when they were tiny, often sold as ‘dwarf’ conifers by unscrupulous (or ignorant) sellers in the 1970s. Even experienced gardeners can fall foul of planting trees near houses. In my case, a now huge Phormium in the front garden was sold as a ‘medium-sized’ plant.
Remember, roots often extend further than the MATURE height of the tree, taking moisture from the soil. The distinction between shrubs and trees is also fuzzy. A large shrub is often bigger than a small tree. When in doubt, CHECK THE FINAL HEIGHT AND SPREAD.
Planting trees near houses – top tips
The National House Building Council (NHBC) has these tips on planting new trees near your home:
- On clay soil, new planting may cause it to shrink, while removing trees and shrubs may make it swell. Plant new trees away from your home. Find out the mature height and position it at least three-quarters of this distance from the house.
- High water demand trees (elm, eucalyptus, oak, poplar, willow and common cypress species) should be planted no closer than one-and-a-quarter times the mature height.
- Climbers such as ivy and Virginia creeper have aerial rootlets or twining tendrils which can damage loose mortar. Plant these at least three meters away from your home.*
- Mature trees can be protected by law – check before you prune or cut one down. Ask your local authority about planning conditions, conservation area restrictions or Tree Preservation Orders.
- Allow enough room for trunks and large roots to grow safely if planting trees near houses. Be careful if planting near drains or lightweight structures.
- Ask neighbours if planting a tree near their property is OK, especially if it will cut off their light. You could be liable for repairs if your trees cause damage to their home.
- Regular pruning of fast-growing trees such as the Leyland cypress (Leylandii) or eucalyptus will reduce the amount of water taken from the soil.
- The soil level around your home should be kept below the damp proof course (150mm or two brick courses). Paths should be the same, except where they have been designed to provide level access into the home. Air bricks, permanent ventilators or perpend vents should not be blocked or covered by soil or paving.
Giving ivy a bad name
This I take issue with. Ivy, especially, has had bad press over the years. As long as the mortar and brickwork are sound, and you keep gutters, the roof and windows free from climbers, there is evidence to suggest they can provide insulation, as well as provide wildlife habitats.
Further advice on property maintenance can be found in NHBC’s A Guide to your new home – a practical guide to looking after your new home, available at www.nhbc.co.uk/homeowners.
