
The Billyoh Petra Summerhouse has a high ceiling and large windows to maximise daylight.
It’s available in seven different sizes and is perfect as a sun-room or a garden games room. Choose from EPDM, felt or Shingle roof coverings.
Summary Information – Petra Reverse Apex Summerhouse | |
Roof type | Reverse Apex |
Roof material | 11mm tongue and groove |
Roof covering | Optional extra, sand felt, green mineral felt, grey or black shingles |
Walls | 11mm tongue and groove sections |
Floor | Optional extra, 9mm OSB solid sheet, 10mm durellis sold sheet or 19mm tongue and groove |
Windows | 7 fixed |
Window panes | Single glazed 1.8mm styrene |
Door | Double door with fittings for padlock and internal bolt lock. |
Width x depth | 4.75m x 2.59m / 15’7″ x 8’6″ |
Footprint | 12.3m² / 39’6″ ft² |
Max height | 2.29m / 8’1″ |
Treatment | Optional extra, pressure treated |
Guarantee | n/a |
Price | Click here for current price |
A more detailed review can be found below…
Contents
Economical Summer House
The 16 x 8 version of the Billyoh Petra summer housecosts less than £1000, with the 16 x 10 coming in at just over £1000. For such a large summer house this is a bargain. Smaller configurations cost even less, the 8 x 8 version costs just under £600.
Apex Roof and High Ceiling
If you or your partner are tall then it’s advisable to buy a summerhouse with an apex roof, rather than a flat roof. The height of the apex in the Billyoh Petra is 2.47m, which should mean you can relax and not worry about hitting your head.

The roof braces are positioned slightly lower than the apex to provide roof support but are still above 2 metres high. The door height is 1.64m, low-ish doors are a feature of nearly all garden buildings.
Tall Shatter Resistant Windows
The 16 x 8 version of the Petra has six tall windows along the front, with a double door which will allow you to cool down in the summer months. A double door is useful for carrying in furniture or if you’ll be using the building to store lawnmowers or other large objects.

The “reverse apex” orientation of the roof means a wide front which allows a great deal of light to enter. This makes it a popular choice for a wide range of uses, from a relaxing second lounge, to garden workshop, to games room.
The windows are 1.8mm thick styrene, a cheaper material which helps keep costs down. Despite it’s low cost it has better insulating properties than glass.
It’s also a shatter proof material, so when a stray football hits the centre pane you’ll breathe a sigh of relief.
Games Room Potential?
If you’re looking to buy a games room in which to place a pool table, you should favour the styrene windows of the Petra. One over-enthusiastic miscue could spell disaster in a glass summerhouse, but the shatter resistant windows of the Petra mean you won’t be picking up shards of glass, a key consideration if this is the plan for your summerhouse.

The best choice for a pool or snooker room is the larger 16 x 10 summerhouse, since it will allow for more cue clearance on each side. A professional pool table measures 8ft by 4ft and you could place it centrally to allow 3 foot clearance.
If that’s still not enough clearance, you could consider the Evolution Garden Office. This is available in a 16 ft x 12 ft size, although it costs significantly more than the Petra.
Building Use and Floor Reinforcements
Depending on the what you’ll be using the building for, you may want to consider a thicker floor. A 19mm tongue and groove floor is a good upgrade choice available when ordering. You can also choose from a variety of other customisation options, including shelving for one, two or three sides and lots of different roofing options.
Roof Coverings: Felt, EPDM, Shingles
You will need to consider how to protect your roof, especially if you live in a rainier region of the UK such as Manchester or Cardiff.
There are five roofing options available, which in order of cheapest to most expensive are:
- Sand felt
- Green mineral felt
- EPDM rubber roof
- Grey roll on shingles
- Black shingles and eaves capping

Shingles are a great option and have the advantage of being very visually appealing. A shingle roof is considered the gold standard and will add a touch of class to your building.
An EPDM rubber roof is another popular option, it’s environmentally friendly and should last fifty years, at the end of it’s useful life it can be fully recycled.
Additional Heavy Duty Roof Option
If you need a reinforced roof select the “heavy duty” option which includes additional roof trusses to strengthen the interlocking 11mm tongue and groove boards.

Sections For Ease of Assembly
The strong tongue and groove design is delivered in sections which make assembly less daunting. Comprehensive assembly instructions are also included. If you have DIY experience and a willing helper you should be able to manage the build. If you can rope in some more friends you may be able to take on the role of “project manager” and issue instructions whilst “overseeing” with a cup of tea in your hand.
All of the sections and panels are provided in a size which can fit through standard doors. If access to your back garden is difficult this shouldn’t be a problem; the sections can just be carried through your house.
Garden Building Best Seller
The Petra is an affordable option which can be used for a variety of uses and comes in multiple different sizes to suit any garden. This explains why its one of the best sellers from “garden buildings direct”.
It’s manufactured by the British company BillyOh, renowned for their build quality and able to deliver promptly across the UK. Click here to visit the retailer.