Decking transforms how you use a garden. It creates a defined outdoor room, a space that sits somewhere between the house and the planting, usable from March through to October if you get the details right. We have designed and built decked areas in gardens across Kent, Surrey, Essex and London, from compact urban courtyards to sprawling country properties, and the conversations always start the same way: what material, how much, and will it actually look good in five years?
This guide answers all of that. We cover materials and their real costs, layout ideas for every size of garden, planting to soften the edges, lighting, maintenance and the planning rules you need to know before you start.
Why Decking Works in South East England
The South East has some of the warmest, driest summers in the UK, but also sits on heavy clay across much of Kent, Surrey and Essex. Clay soil is a nightmare for level lawns and traditional paving. It shrinks in summer, swells in winter, and cracks patio slabs over time. Decking sidesteps all of that. The frame floats above the ground on posts or pads, so the subsoil can do what it likes underneath.
Decking also handles slopes well. If your garden drops away from the house, which is common on the North Downs, the Weald and across the Surrey Hills, a raised deck gives you a level entertaining area without the expense of full terracing with retaining walls. We have built raised decks for clients in Sevenoaks, Reigate and Beckenham where the alternative was either accept a sloping garden or spend three times the budget on structural brickwork.
Decking Materials Compared: Timber, Composite and Beyond
The material you choose affects everything: the look, the feel underfoot, the lifespan, the maintenance burden and the cost. Here is an honest comparison based on what we specify and install.
Softwood Timber (Pressure-Treated Pine)
Pressure-treated softwood is the entry point. It is affordable, easy to cut and shape on site, and looks genuinely warm and natural when freshly oiled. The catch is maintenance. Softwood needs oiling or staining every 12 to 18 months to prevent greying, and even with treatment it is more prone to algae growth than composite. Expect a lifespan of 10 to 15 years with proper care.
Best for: budget-conscious projects, DIY builds, gardens where you enjoy the ritual of seasonal maintenance.
Hardwood Timber (Iroko, Balau, IPE)
Hardwoods are the premium timber choice. IPE is extraordinarily dense, naturally resistant to rot and insects, and weathers to a beautiful silver-grey if left untreated. Iroko and Balau sit slightly below IPE in durability but still outperform softwood by a decade. The downside is cost, IPE decking boards alone run to £60 to £80 per square metre before installation, and the timber is brutal on saw blades.
Best for: clients who want natural timber but minimal maintenance, high-end garden builds, south-facing decks that take a hammering from UV.
Composite Decking
Composite boards are a mix of recycled wood fibre and plastic polymer, pressed and extruded into boards that mimic timber grain. The better brands, Trex, Cladco, TimberTech, are genuinely good now. They do not need oiling, they resist algae far better than timber, and they will not splinter. The trade-off is that composite does not feel like real wood underfoot. It gets hotter in direct sun. And the upfront cost is higher than softwood.
We have increasingly specified composite for London balconies and roof terraces where maintenance access is difficult and the client wants a fit-and-forget solution. For more on balcony design, see our balcony garden design guide.
Best for: low maintenance, rental properties, roof terraces, families with small children (no splinters).
PVC Decking
Fully synthetic PVC boards are the most water-resistant option and the easiest to clean. They are lighter than composite, which matters on a roof terrace or raised balcony with weight limits. But they look and feel more plastic than composite, and in our view they suit commercial or poolside applications more than a garden where you want warmth and character.
Material Cost Comparison (2026 Prices, South East England)
| Material | Board Cost per sqm | Installed Cost per sqm | Lifespan | Annual Maintenance |
|---|---|---|---|---|
| Treated softwood | £20 to £35 | £60 to £90 | 10 to 15 years | Oil/stain yearly |
| Hardwood (Iroko/Balau) | £45 to £65 | £110 to £140 | 20 to 30 years | Oil every 2 to 3 years or let silver |
| IPE hardwood | £60 to £80 | £130 to £170 | 25 to 40 years | Oil every 2 to 3 years or let silver |
| Composite (mid-range) | £40 to £60 | £90 to £120 | 20 to 25 years | Annual wash only |
| Composite (premium Trex) | £55 to £80 | £110 to £140 | 25 to 30 years | Annual wash only |
| PVC | £30 to £55 | £80 to £110 | 15 to 20 years | Annual wash only |
Prices include joists, fixings and a weed membrane but exclude steps, balustrades or lighting. For a broader look at garden project costs, our garden design budget guide breaks down everything from design fees to planting.
Garden Decking Ideas by Garden Size
Small Garden Decking (Under 30 sqm)
In a compact garden, decking can actually make the space feel larger. The trick is running the boards in the direction you want the eye to travel. Boards laid lengthways down a narrow garden elongate it. Boards laid across a wide, shallow garden emphasise the width.
For very small spaces, consider decking the entire ground area rather than splitting between deck and lawn. A 4m x 6m courtyard with full decking, raised planting beds at the edges and a couple of statement pots feels generous and intentional. Add fairy lights overhead and it becomes an outdoor dining room. Our courtyard and small garden design guide has more on making tight spaces work.
Budget guide: a 15 sqm softwood deck, professionally installed, runs from about £900 to £1,350. The same area in composite is £1,350 to £1,800.
Medium Garden Decking (30 to 80 sqm)
This is the sweet spot for decking design. You have enough room to create distinct zones: a dining area close to the house, a sun deck further out, maybe a fire pit circle at the far end. Multi-level decking works brilliantly here. A step down of 150mm between zones creates visual separation without barriers, and the change in level signals a different use of the space.
Consider mixing materials. A main deck in composite or hardwood with a gravel or paving strip separating it from a lower lawn area creates contrast and makes both surfaces look better. We often specify a 600mm border of sawn sandstone or porcelain between the deck edge and the planting to give a clean transition.
Budget guide: a 30 sqm composite deck with one step change runs from about £2,700 to £3,600 installed. Add a simple glass balustrade on a raised section and you are looking at another £800 to £1,500.
Large Garden Decking (80 sqm+)
In a large garden, decking should not dominate. It works best as one zone within a larger scheme, perhaps wrapping the rear of the house and extending to the edge of a terrace, with steps down to a lawn or planting area below. Full coverage decking in a big garden looks like a car park. Use it strategically.
Raised decks on sloping sites can incorporate storage underneath for bikes, logs, garden furniture covers and tools. We have designed raised decks with built-in bench seating along the perimeter, which doubles as storage and removes the need for separate garden furniture. For more on working with slopes, our sloping garden design guide covers terracing, retaining walls and drainage.
Budget guide: a 50 sqm hardwood deck with balustrades, steps and integrated lighting starts from about £7,500 to £10,000 installed.
Design Ideas That Actually Work
Diagonal Board Laying
Laying boards at 45 degrees to the house makes any deck feel more designed and less like a standard builder fit-out. It does use about 15% more material due to cuts, but the visual payoff is significant, especially on a square deck where parallel boards can look monotonous.
Built-In Seating and Planters
Integrated bench seating along one or two edges of a deck eliminates the need for bulky garden furniture. Build it 450mm high (standard seat height) and 400mm deep, with a backrest angled at about 10 degrees for comfort. Pair it with built-in planters at the corners filled with architectural plants like Phormium tenax (New Zealand flax), Hakonechloa macra (Japanese forest grass) or clipped Buxus sempervirens (box balls).
Mixed Surface Decking
Combine wider and narrower boards, or alternate two complementary composite colours in a banding pattern. Charcoal and mid-grey, or walnut and teak tones, create a contemporary striped effect. Keep it to two colours maximum or it starts looking fussy.
Floating Deck Platforms
A freestanding deck platform set into the garden, away from the house, creates a destination within the planting. Picture a 3m x 3m hardwood platform surrounded by ornamental grasses, with a pair of sun loungers. It turns an underused section of lawn into a second living space. These are simpler to install than attached decks since they do not need ledger boards fixed to masonry.
Deck and Water Feature
Decking and water complement each other beautifully. A recessed channel built into the deck edge with a stainless steel water blade, or a self-contained corten steel water bowl set into a cut-out in the boards, adds sound and movement. We have used this combination in several projects, and the reflections of planting in the water, framed by the clean lines of the deck, create something genuinely special.
Planting Around and Through Decking
The biggest mistake with decking is treating it as a hard surface surrounded by nothing. Planting transforms a deck from a wooden platform into an integrated garden space. Here are the plants we specify most often around decked areas in the South East.
For Sunny Decks
Lavandula angustifolia 'Hidcote' (English lavender) in a border along the deck edge. Height 60cm, flowers June to August, drought tolerant once established. About £5 to £8 per plant in a 2-litre pot.
Verbena bonariensis planted in drifts behind the lavender, giving tall, airy purple flower heads from July through to the first frosts. Self-seeds readily. About £4 to £6 per plant.
Stipa tenuissima (Mexican feather grass) in groups of three or five at the corners of the deck. The movement in the breeze is mesmerising, and it catches the evening light beautifully. About £6 to £9 per plant.
For Shady Decks
Hakonechloa macra 'Aureola' (golden Japanese forest grass) in pots on the deck itself or in raised beds at the edges. Tolerates full shade, lovely golden-green cascading habit. About £8 to £12 per plant.
Fatsia japonica for bold, architectural foliage in a sheltered corner. Hardy to minus 10 in the South East. A single specimen in a large pot or planting bed anchors the whole design. About £15 to £25 for a 5-litre plant.
Hydrangea anomala subsp. petiolaris (climbing hydrangea) trained up a wall or fence behind the deck. Self-clinging, shade-loving, white lacecap flowers in June. One of the best climbers for a north-facing wall. About £12 to £18 per plant.
For Deck Edges and Gaps
Erigeron karvinskianus (Mexican fleabane) tucked into the gap between the deck edge and a wall or paving. It self-seeds into cracks and produces tiny daisy flowers non-stop from May to November. Costs almost nothing, about £3 to £5 per plant, and does all the work itself.
Lighting Your Deck
Deck lighting extends usability into the evening and adds atmosphere you cannot get any other way. The key is layering: low-level and accent, never floodlighting.
Recessed deck lights set into the board surface at the edges of steps. LED, warm white (2700K to 3000K), typically 30mm diameter. About £15 to £25 per fitting. Plan for one every 400mm on step risers.
Post-mounted downlights on balustrade posts, casting a soft pool of light downward. Better than uplights for a deck because they reduce glare and do not blind anyone sitting down.
Festoon lights strung above the dining area on stainless steel catenary wire. The old classic. Warm white, not cool white. About £25 to £40 for a 10m string. Nothing else creates that relaxed, end-of-summer-evening feeling quite like them.
For a deeper dive into garden lighting, including voltage options and installation, see our garden lighting guide.
Planning Permission and Building Regulations
Most garden decking falls under permitted development and does not need planning permission, but there are conditions. In England, decking is permitted development as long as:
- The deck is no more than 300mm above the existing ground level at any point
- Together with other extensions and outbuildings, it does not cover more than 50% of the total curtilage (garden area)
- It is not built forward of the principal elevation facing a highway
- It is not on a listed building or in a conservation area without prior approval
Raised decks that exceed 300mm from the ground, which is common on sloping sites, will typically need a planning application. The 300mm rule catches a lot of people out. If your garden slopes and the rear of the deck is 500mm above ground, even though the front is at ground level, you need planning permission for the whole structure.
Building regulations generally do not apply to decking under 600mm high that is not attached to a dwelling. Above 600mm, or if you are building a balustrade over 600mm high, building control may want to get involved. Our guide to garden room planning permission covers the broader rules for structures in gardens.
Maintenance: Keeping Your Deck Looking Good
Timber Decking Maintenance
Oil or stain softwood decking at the start of each season, around April in the South East. Clean first with a stiff brush and a purpose-made deck cleaner (not bleach, which damages timber fibres). Let it dry for at least 48 hours, then apply two coats of decking oil. Osmo and Ronseal both make good products. Budget about £40 to £60 per year for a 20 sqm deck.
Algae is the perennial problem with timber decking in the UK climate. Keep the deck swept clear of leaves, which trap moisture and encourage growth. Anti-slip deck strips cost about £2 to £4 per metre and are worth fitting on steps and shaded areas.
Composite Decking Maintenance
An annual wash with warm soapy water and a soft brush is all composite needs. Pressure washers work but use the fan nozzle on a low setting, not the pencil jet. Never use wire brushes. Composite can stain from BBQ grease or red wine, so wipe spills quickly. That is genuinely it.
Decking vs Paving: Which Is Right for You?
This comes up in almost every initial consultation. Here is the honest answer.
Decking is faster to install, usually cheaper per square metre, better on slopes, warmer underfoot, and easier to run cables beneath for lighting and speakers. It gives a softer, more relaxed feel than stone.
Paving (natural stone or porcelain) lasts longer with less maintenance, feels cooler in summer, does not need any treatment, and suits more formal garden styles. It also works better as a direct transition from indoor flooring, especially if you match the paving to internal tiles for a seamless inside-outside connection.
We often combine both. A paved dining terrace closest to the house, with a deck platform further down the garden as a sunbathing or lounging area. The contrast between the two surfaces defines the zones without needing any barriers. For more on paving options, our garden patio ideas guide covers materials, costs and layout in detail.
How We Design Decked Gardens
Every garden we design starts with a site visit and a conversation about how you want to use the space. For decking projects, we look at:
- Orientation, where the sun falls at different times of day, because this determines where the deck should sit
- Levels, whether the garden slopes and how much excavation or raising is needed
- Access, how materials will get into the garden (critical in terraced London properties with no side access)
- Drainage, especially on clay soils where water pooling under a deck can cause problems
- Neighbours, privacy screening, overlooking, boundary considerations
We produce detailed hand-drawn plans and 3D visualisations so you can see exactly how the deck, planting, lighting and furniture work together before any construction starts. This is where the design fee pays for itself, because changing a line on a drawing costs nothing. Changing a built deck costs thousands.
If you are thinking about a decking project, whether it is a small balcony, a courtyard, or a full rear garden redesign, we would love to hear from you. Call us on 0203 834 9807 or get in touch through our website for a free initial consultation.
Frequently Asked Questions
How much does garden decking cost in the UK in 2026?
For a professionally installed deck in the South East, expect to pay £60 to £90 per sqm for softwood, £90 to £120 per sqm for composite, and £110 to £170 per sqm for hardwood. A typical 20 sqm softwood deck costs around £1,200 to £1,800 installed. These prices include joists, fixings and a weed membrane but not steps, balustrades or lighting.
Is composite decking worth the extra cost?
In most cases, yes. Composite costs about 30 to 50 percent more than softwood upfront but needs almost no maintenance over a 20 to 25 year lifespan. Softwood requires annual oiling or staining, which adds up to hundreds of pounds over a decade. If you value your weekends more than the saving, composite is the better long-term investment.
Do I need planning permission for decking?
Not usually. Decking under 300mm from the ground, covering less than 50% of the garden, is permitted development in England. Raised decks over 300mm need planning permission. Listed buildings and conservation areas have additional restrictions. Always check with your local planning authority if you are unsure.
What is the 300mm rule for decking?
Under permitted development rules, any decking platform that rises more than 300mm above the existing ground level requires planning permission. This is measured at the highest point, so if your garden slopes and the far edge of the deck is 350mm above ground, the entire deck needs a planning application even if the front edge is at ground level.
Can I lay decking over an old patio?
Yes, as long as the patio is structurally sound and reasonably level. You will need to fix battens to the paving to create a frame for the deck boards, and ensure adequate drainage so water does not pool underneath. This is actually a quicker and cheaper option than lifting the old paving.
What is the best decking for a shady garden?
Composite is the best choice for shady spots. It resists algae growth far better than timber and does not need the annual oiling that softwood demands. If you prefer timber, fit anti-slip strips and keep the deck swept clear of leaves to reduce moisture and algae buildup.