Monday, 23 January 2017

Sloping Garden Design Challenges

I specialise in designing sloping gardens, and the are always tough to get right.  The challenges of landscaping a steep garden can be summarised as follows:-

1. How to create flat, usable spaces

This is the trickiest part.  The only way to get flat areas that can be used for seating areas, lawns, garden buildings, etc on a sloping site is to cut into the slope and build a retaining wall to hold back the soil from the higher parts of the garden.

 Sloping garden design Kenley, Surrey

Walls should be no more than 1m high, any higher and you'll need to ask the advice of a structural engineer in order to ensure they will be strong enough.  Ideally, put in more, lower walls and create multiple terraces.

Sloping garden design Reading, Berkshire

Many people make the mistake of taking the highest point of their garden and building out from there, putting in huge raised decks and patios.  This is not only antisocial - it creates a platform from where you can view all your neighbours' gardens - it is also illegal.  There is a piece of planning legislation in the UK that prohibits the raising of the existing ground level by more than 150mm and it was designed to prevent exactly this situation.  Instead, dig into the slope and reduce the ground level to it's lowest point.  This way you and your neighbours will retain privacy when using your gardens.

Sloping front garden design Woking, Surrey
2.  How to access all the garden safely

Having created terraced, flat areas you'll need to get to them in order to use and maintain them.  Ramps can be tricky as they should not be too steep and therefore need quite a lot of space to keep the rise over their length to a comfortable incline.  Steps are usually best in a small space, but will make it difficult to get lawnmowers and other heavy garden equipment up and down the garden.  Step risers in a garden should be lower than those inside the house - no more than 150mm high. Step treads should be at least 300mm deep - I always make them deeper. 

 Sloping garden design Gerrards Cross, Buckinghamshire
3.  How to use the garden safely

Railings will be needed to prevent accidents.  A wooden, or metal railing of 1.2m high will prevent people from inadvertently stepping off the terraces or pushing out a chair too far.  Railings can be fixed to the tops of retaining walls or set inside borders adjacent to the walls.

Sloping garden design Binfield, Berkshire
4.  How to create borders

It is hard to get larger shrubs and trees to establish and grow well on slopes, so this is another case where flat spaces are required.  In the same way you need terrace for seating areas and lawns held in place by retaining walls, planted borders are much better if they are flat.  Build retaining walls and give your plants a level surface so they can establish without being staked and so that water will stay around their roots rather than running off down the slope.

Sloping garden design Sunningdale, Berkshire
5.  Drainage

If you are putting in paving around the house and the slope falls towards the house you'll need to put in some extra drainage to ensure the patio doesn't fill up with water and flood the house.  A simple slot type drain routed into a soakaway is usually sufficient unless you have particular problems with drainage - heavy clay or a high water table, for example.

Sloping garden design Bracknell, Berkshire

6.  Cost

It's pointless to pretend all this excavation and construction of retaining walls doesn't come at a cost.  Building a sloping garden can be very expensive and even in a small garden you'll need to allow upwards of £30,000 just for the hard landscaping.  Many people don't realise how much it costs to get rid of soil and other material that is left over from excavating the bank and digging wall foundations.

 Sloping garden design Guildford, Surrey

However, if you can spend the money you will be left with a spectacular garden that has interest and a wonderful varied journey even in the smallest space.  The level changes add dynamism and drama to the space and also look wonderful when lit up at night.  Improving a sloping garden so that it is useable and beautiful will also add value to your property and make it easier to sell if you decide to move.

If you would like help designing your garden, please drop me an email, or visit my Web site for telephone contact details.  You can also see examples of my work on my Facebook page and Houzz profile.

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