Underground Shelter
An underground shelter can provide a secure, protected space that could also be used for long-term storage or as an emergency living area. Modern underground shelters are available commercially in the UK, ranging from relatively simple buried structures to fully equipped installations with sleeping areas, kitchens, toilets, water supplies, ventilation and air filtration.
A shelter does not necessarily have to resemble a traditional military bunker. A professionally designed installation can be relatively small and discreet, while providing many of the facilities required to remain underground for an extended period.
Do underground shelters have to be built from scratch?
Not necessarily.
There are now several UK companies specialising in underground shelters and bunkers. Some manufacture prefabricated underground structures that are installed on site, while others provide more complete systems including excavation, installation, ventilation, electrical systems, plumbing and interior fit-out.
This means that an ordinary builder would not necessarily need to design and construct the underground structure themselves. Using a specialist company has the advantage that the structure and its essential systems can be designed together from the beginning.
There are broadly three approaches:
- A complete professionally installed shelter, including the structure and internal systems.
- A prefabricated shelter installed by specialists, with the interior subsequently fitted out to suit the owner.
- A completely bespoke underground structure, designed specifically for a particular property.
For a typical domestic installation, a professionally designed and installed system is likely to be the most practical approach.
What does an underground shelter need?
An underground room intended for emergency occupation requires considerably more than a strong structure buried in the ground.
The essential systems include:
Structural protection
The structure must be capable of supporting the weight of the surrounding ground and anything above it. It also needs to remain watertight and resist the effects of groundwater and changes in ground conditions.
Commercial shelters use a variety of construction methods, including reinforced concrete, steel and high-density polyethylene structures.
Secure access
The entrance needs to provide protection while still allowing occupants to enter and leave safely.
A discreet entrance could potentially be incorporated into an existing building or garden structure, depending on the design and location.
An emergency escape route is also an important consideration. A shelter with only one entrance could become unusable if that entrance were blocked.
Ventilation
Ventilation is one of the most important systems in an underground shelter.
An underground room cannot simply be sealed and occupied indefinitely. Fresh air must continually be supplied and stale air removed.
Specialist shelters can incorporate mechanical ventilation systems and, where required, filtered air systems designed to protect against airborne contaminants.
Water
A shelter intended for extended occupation needs a reliable supply of drinking water.
This could be provided by stored water, a connection to the mains supply, or a combination of storage and treatment systems.
Water for washing and other purposes also needs to be considered.
Sanitation
A normal underground room cannot necessarily rely on the existing household drainage system.
A toilet and wastewater system therefore need to be incorporated into the design. Commercial shelters can use systems such as composting toilets, holding tanks and pumps depending on the installation.
Electricity
Electricity is required for lighting, ventilation, communications, refrigeration, pumps and many other systems.
A connection to the mains supply can provide normal power, but an emergency shelter should ideally have an independent backup system.
Battery storage, generators and solar charging can all be considered depending on the available space and budget.
Heating
The surrounding ground provides considerable thermal insulation, but an occupied underground room will still require temperature control.
Heating also needs to be considered alongside ventilation and electrical requirements.
What can be included?
Modern underground shelters can contain considerably more than the basic necessities.
Depending on the size and budget, an installation could include:
- Bed or sleeping area
- Food storage
- Kitchen
- Refrigerator
- Drinking-water storage
- Water filtration
- Shower
- Toilet
- Hot-water system
- Heating
- Mains electricity
- Battery backup
- Solar charging
- Emergency lighting
- Mechanical ventilation
- Air filtration
- Communications equipment
- Internet connection
- Radio
- Seating
- Table or workspace
- General storage
The difference between a basic emergency shelter and a comfortable long-term shelter is largely a matter of space, equipment and budget.
A relatively small shelter could provide the essentials, while a larger installation could effectively become a small underground living space.
What is available commercially?
Burrowed
Burrowed is a UK company specialising in prefabricated underground structures.
Its shelters can be supplied as structures for customers to fit out themselves or as professionally installed systems.
The company’s more complete specifications can include an airtight door, emergency escape hatch, fresh-water storage, water filtration, shower, water heating, grey-water storage and pumping, kitchen facilities, food storage, beds, sofa bed, bathroom, composting toilet, lighting, mains electricity, battery and solar charging and a four-stage air-filtration system.
Burrowed also offers professional installation involving excavation, installation of the structure, backfilling and connection of services.
This makes it one of the closer commercial examples to a fully equipped underground living space.
Fortis Shelters
Fortis Shelters offers a different type of underground shelter.
Its current range includes a fully buried Type 1 shelter listed at approximately £40,700, and a partially buried Type 2 listed at approximately £41,800.
The shelters use HDPE construction and incorporate ventilation and air-handling systems. The partially buried design can be useful where a deep excavation is undesirable or where site conditions make a shallower installation preferable.
The published prices cover the shelter itself and its core systems, but additional work such as excavation, crane hire, electrical connection and interior comforts can increase the final cost.
This illustrates an important difference between buying a shelter and buying a complete underground living facility.
Affordable Bunkers
Affordable Bunkers offers a more traditional reinforced-concrete approach.
Its advertised bunker is approximately 4.8m × 4.8m × 2.4m, giving roughly 23 square metres of internal floor area.
The current advertised price is approximately £49,950 and includes excavation through to handover, together with the reinforced-concrete structure, heavy-duty door, air filtration and survival equipment.
A shelter of this size is large enough to provide separate areas for sleeping, storage, living and sanitation rather than simply functioning as a single emergency room.
How much does an underground shelter cost?
Published prices provide a useful starting point, but the final cost can be considerably different from the headline price.
The total cost can depend on:
- Size of the shelter
- Construction method
- Depth
- Ground conditions
- Water table
- Excavation requirements
- Access to the property
- Removal of excavated material
- Crane requirements
- Drainage
- Electrical connections
- Water connections
- Ventilation
- Air filtration
- Internal fittings
- Planning and professional fees
Current advertised prices demonstrate that professionally manufactured shelters can begin in the region of £40,000–£50,000, but a fully equipped installation could cost considerably more.
The site itself may ultimately be as important to the cost as the shelter.
Where could a shelter be installed?
There are two obvious possibilities: beneath an existing building or separately within the garden.
Beneath the house
An underground shelter beneath a house provides an attractive solution because access could potentially be incorporated into the building.
A discreet entrance could, for example, be incorporated into a storage cupboard or another part of the property.
However, excavating beneath an existing house is technically challenging.
The foundations may need to be supported or underpinned, and underground drains, water pipes, gas supplies, electrical cables and other services may be present.
The structural implications can therefore make an underground room beneath an existing house considerably more complicated than installing a separate structure elsewhere on the property.
Beneath the garden
A separate garden installation may provide greater flexibility.
The shelter can be positioned away from the existing foundations, while the entrance could potentially be incorporated into a garden building or other structure.
However, the available access for excavation equipment, the location of underground services, groundwater and the distance from neighbouring properties still need to be considered.
A garden installation is therefore not automatically simple, but it may avoid some of the structural problems associated with excavating beneath an existing house.
Planning and Building Regulations
An underground shelter is a substantial construction project rather than simply a piece of garden equipment.
Creating a new basement or underground structure may require planning permission, and Building Regulations can apply to matters including structure, fire safety, ventilation, damp protection, electrical installations and water supplies.
The Planning Portal notes that basement construction can involve significant structural and planning considerations.
Work close to neighbouring properties can also introduce Party Wall considerations.
The exact requirements depend on the property, location and proposed construction, so a professional project would need appropriate architectural, structural and planning advice before excavation begins.
How discreet can an underground shelter be?
An underground shelter does not necessarily need to be obvious from above.
The majority of the structure can be below ground, leaving only the access arrangements and ventilation systems visible.
A discreet entrance could potentially be incorporated into an existing building, storage area or garden structure.
However, there is an important distinction between a discreet shelter and an unapproved or concealed construction project.
The structural engineer, contractor and relevant authorities need to know what is actually being constructed so that the structure, ventilation, fire safety, drainage and other systems can be designed correctly.
The interesting question is therefore not whether an underground shelter can be built without anyone knowing about it, but how unobtrusive a properly designed and approved shelter could be made.
The ideal domestic underground shelter
A practical domestic shelter does not need to be enormous.
A relatively compact installation designed for two people could potentially provide:
Sleeping area
A proper bed or folding sleeping arrangement.
Food storage
Shelving and storage designed to accommodate a substantial supply of food.
Water
Stored drinking water together with filtration or treatment equipment.
Bathroom
Toilet, washing facilities and appropriate wastewater storage or disposal.
Kitchen
A small food preparation and cooking area.
Power
Mains electricity with battery backup and potentially solar charging.
Ventilation
Continuous mechanical ventilation with appropriate filtration.
Communications
Radio, telephone/mobile communications and internet where available.
Storage
Space for clothing, tools, medical supplies and other emergency equipment.
Comfort
Heating, comfortable seating, lighting, entertainment and other inexpensive additions that would make an extended stay considerably more tolerable.
The objective would not necessarily be to create a place where people could live permanently underground. Instead, the aim would be to create a self-contained emergency shelter capable of supporting its occupants for an extended period.
The next question: what would it really cost?
Commercial underground shelters already provide many of the facilities required for this type of installation.
The next stage is therefore to look beyond the basic advertised bunker prices and calculate what would be required to create a genuinely comfortable two-person shelter.
This means considering the cost of:
- The underground structure
- Excavation and installation
- Entrance and emergency escape
- Waterproofing and drainage
- Ventilation and air filtration
- Water storage and treatment
- Toilet and sanitation
- Electricity and backup power
- Heating
- Food storage
- Sleeping arrangements
- Kitchen facilities
- Communications
- Interior fittings
- Basic comforts
The result should provide a realistic indication of whether a professionally installed underground shelter is something that could be achieved for £50,000, £100,000 or considerably more.
It will also show which features are essential and which are simply luxuries.