Testing labs in Wraxall

Building Analysis & Testing Ltd (BAT) is a specialist construction testing and consultancy company headquartered at Lower Ground Floor, School House, Bristol Road, Wraxall, Bristol BS48 1LE. Operating since 2006, with the company's founding director having begun building air-tightness testing as far back as 2003, BAT has accumulated over two decades of practical experience in the field of building performance verification. The company operates as a mobile testing laboratory covering England and South Wales, attending client sites to conduct compliance and performance testing that satisfies statutory requirements under UK Building Regulations. BAT serves residential, commercial, and industrial clients including housebuilders, main contractors, architects, design teams, and building owners who must demonstrate regulatory compliance at practical completion or during retrofit projects. BAT's primary specialism is air leakage and air permeability testing carried out in accordance with Building Regulations Part L, which governs the conservation of fuel and power. For domestic dwellings (L1 buildings), engineers deploy calibrated Retrotec DoorFan blower-door units to pressurise or depressurise the building envelope to 50 Pascals, measuring the resultant air flow to derive an air permeability result expressed in m³/hr.m² at 50 Pa. Current Building Regulations set a maximum allowable air permeability of 8 m³/hr.m² (revised June 2022), though SAP energy calculations frequently mandate more onerous targets of 5 m³/hr.m² or even 3 m³/hr.m². For commercial and large-scale buildings (L2), BAT utilises multiple simultaneously deployed Retrotec units or a trailer-mounted vehicle fan rig with its own generator to test warehouses, office blocks, accommodation buildings, retail premises, and large-scale industrial facilities. All engineers are registered with the Air Tightness Testing and Measurement Association (ATTMA) Competent Persons Scheme and are individually qualified to ATTMA L1 (domestic) and L2 (commercial) test levels, ensuring that lodged certificates are accepted by building control authorities across England. For buildings pursuing Passivhaus certification—either new-build or deep-retrofit projects—BAT engineers hold the specific training and qualifications required to conduct Passivhaus air leakage testing, which typically demands a far more demanding target of 0.6 air changes per hour at 50 Pa (n50). BAT additionally performs low-leakage testing for projects with particularly stringent energy performance targets that exceed standard Building Regulations requirements, applying the same rigorous calibrated methodology and traceable equipment to satisfy certification body requirements. Beyond conventional envelope testing, the company's specialist capabilities extend to Fire Integrity Testing of compartmentation elements, Floor Void Testing, Smoke Shaft Testing, and Isolation Room Testing performed to the HBN 04 Supplement 1:2013 standard used for healthcare and laboratory environments—demonstrating a breadth of pressurisation-based testing well beyond the typical air-tightness contractor. Building Regulations Part E acoustic compliance is a further core service line. BAT's engineers conduct airborne and impact sound insulation testing between dwellings and between dwellings and communal areas, providing results in the form of DnT,w and L'nT,w values to confirm compliance with Approved Document E separating-element standards. Where projects require it, noise surveys for planning purposes are also undertaken, providing measurement data to support planning applications or condition discharge relating to ambient noise levels. Thermal imaging surveys are carried out using specialist infrared thermography equipment, with BAT being a member of the UK Thermography Association; these surveys can satisfy BREEAM credit requirements and are also employed for qualitative diagnosis of thermal bridging, moisture ingress, and heat loss pathways in the building envelope. Domestic ventilation commissioning and testing under Building Regulations Part F forms an additional service strand. BAT employs engineers qualified under the NICEIC Competence scheme for the commissioning and measurement of domestic ventilation systems. Air flow rates at each terminal are measured and compared against design targets specified under Part F, providing compliance evidence and identifying underperforming systems. Because ventilation performance is closely linked to the air permeability of the building envelope, BAT regularly combines air leakage testing and ventilation commissioning on a single site visit, reducing overall programme disruption and test costs for clients. BAT has held UKAS (United Kingdom Accreditation Service) accreditation as a mobile testing laboratory since the company's inception, covering both air permeability testing and sound insulation testing to the prevailing national and international standards. UKAS accreditation operates in accordance with ISO/IEC 17025, the international standard for the competence of testing and calibration laboratories, providing independent third-party assurance that BAT's measurement systems, calibration traceability, personnel qualifications, and quality management processes meet rigorous benchmark requirements. Alongside UKAS accreditation, BAT maintains active membership of ATTMA, which introduced its Competent Persons Scheme in 2015 to ensure that only organisations with demonstrated competence and calibrated equipment may lodge test certificates. Equipment calibration is maintained in accordance with scheme requirements to preserve metrological traceability on all reported results. A distinguishing feature of BAT's model is the integration of pre-test construction consultancy with test delivery. At early design stages, BAT's engineers—who hold backgrounds in construction and mechanical and electrical engineering—review proposed detailing and material specifications to identify airtightness risks before they are built in. At construction stage, consultancy site visits at key milestones allow the team to work alongside contractors to address deficiencies before the formal compliance test, substantially improving first-time pass rates. This consultancy-led approach has particular value on projects with onerous energy targets, complex construction interfaces, or constrained programmes. For clients requiring additional flexibility, BAT offers testing outside standard working hours including evenings, weekends, and overnight where building operation or handover schedules make daytime access impractical, covering all locations throughout England and South Wales from its Bristol base.