Different types of basement: our guide to basement grading

With space tighter than ever in many cities and towns, it’s no surprise that basements are once more gaining in popularity. As an effective way to extend your space downwards rather than outwards, structural engineer London services are doing more work on basements than ever before. But when it comes to the specifications and types of basement out there, the jargon can be confusing for the average homeowner.

Divided into specific types and grades, there’s more than one way to do a basement. But to find a solution that works for you, it pays to know what each type means – plus the benefits of picking that particular model. Perhaps you want to rejuvenate an unused space in your home. Maybe you’re considering building a brand-new basement maximise space. Whatever your need for a professionally-finished basement, we’ve got all the information you need to get started.

Read on to find out more about the different grades and types of basement – and why each type might be the best fit for your specific needs:

Type A, B and C basements

Before you get into the specialist details and information about your choice of basement, it’s best to start with the basics. For any basements that require new build planning permission London, an effective waterproofing system is needed. These different types of protection prevent basements from flooding or becoming damaged over time, which can be a severe concern for urban basement building – especially in areas like London.

These different types of water resistance are specified under BS 8102 and are necessary for anyone looking to build a safe, structurally sound basement addition to their home. So, when we talk about structural engineer services London for basements, what do these types mean? Here’s the basic rundown of the differences between each option:

Type A basements

Type A basements are defined as any basement that uses a form of barrier or membrane protection to ensure the water tightness of a basement space. This barrier may be made of specified waterproofing material combined with reinforced concrete and blockwork. The general idea of this waterproofing method is that it offers an additional layer of waterproofness to a space, as materials like brickwork and concrete may be porous or damaged by water over time.

Type B basements

For basements using type B waterproofing, structural integrity is the primary way in which the basement is protected from water damage and ingress. This means that professional structural engineering services will be required to appropriately create a waterproofed space, using anything from reinforced concrete slabs to specialist water stop features in design work to achieve the desired results. While more involved, this method is also highly effective, where type A basements may not be a suitable solution.

Type C basements

The final defined basement type, type C basements utilise drainage protection to keep basements waterproof and damp-free. By installing and implementing cavity drain membranes, any excess water can find its way into a provided drainage system into of seeping through walls and flooring. While expensive, this solution is an excellent fit for many basements – particularly in areas where water levels are higher.

Basement grading

Alongside the waterproofing requirements specified for basement types, grading is another way in which basements can be defined under the BS 8102, as of 2009. These specific grades relate to the usage of the basement itself and provide requirements regarding each specific level or grade. This includes anything from acceptable temperatures due to wetness and humidity in the basement areas.

Four grades are defined under this scale, each of which has an increasing amount of requirements and performance levels to be suitable for use. The scale is as follows:

Grade 1 – basic utility basements

These basements can be used for plant machinery as well as car parks and worktops. Grade 1 is the lowest grade of usability on the scale, and requires far fewer specifications than other levels. Some damp and water seepage is acceptable for grade 1 basements, with specific temperatures defined for different uses where the machinery may directly affect the humidity and heat within a room.

Grade 2 – improved utility basements

Grade 2 basement is also specified for use as plant and workshop rooms; however, this grading is designed for environments that need to be drier than is possible for grade 1 structures. This means a lower humidity, no damp or water seepage, and reasonable ventilation requirements in specific circumstances. This grade of basement s also considered suitable for retail storage.

Grade 3- habitable basements

For many homes and households, this is the grade of basement required for a useable basement within your property. Designed to be used for residential and commercial purposes, grade 3 basements require the use of ventilation, as well as active dampness reduction and specific temperatures depending on the exact purpose of the room itself.

Grade 4 – special basements

For the vast majority of properties, the requirements for grade 4 basements go above and beyond their requirements. These particular basements are designed for controlled environment storage, including for archiving documents, microfilms and even valuable artwork. It’s a must for grade 4 basements to be 100% dry, with controlled humidity and temperature.

To be in-line with building regulations Wembley, as well as for the broader area of London, understanding the types and grades of buildings is the place to start. As qualified, professional structural engineers in the London area, we’re equipped with the expertise and knowledge to create basement spaces perfectly in-line with the requirements of BS 8102. This means basements that last, look great and are entirely damp-free.

If you’re interested in expanding your property downwards, then our team are the ideal people to call to get the ball rolling. We’re well-equipped to create functional, beautiful and long-lasting basement spaces for your property, in line with planning permissions and building regulations Gerrards Cross and beyond. Get in touch with AC Design Solutions today to discuss how we can maximise the space in your home with the ideal basement conversion and installation.