Purpose of this Report
The overall purpose of this report was to identify current relevant legislation, and to interpret and critically appraise the impact of primary legislation and methods of compliance using the appropriate technical guidance.
Brief
This report is in relation to Part F of the Building Regulations (Northern Ireland) 2012, particularly with respect to methods of achieving compliance in non-domestic buildings (Part F2).
The following points are covered with this report;
1. Identification and description of the suitable legislation and the context in which the legislation functions.
2. Discussion on the considerations and procedures for compliance with the regulations in the context of a proposed extension stated within the Building Reference section.
3. A critical evaluation of the implications of the required regulatory approach on the fabric and services of the existing building.
Building Reference
Proposed extension of 350m2 (floor space) to an existing retail premises with an existing floor space of 1200m2. Steel framed portal frame construction with composite insulated cladding and ppc aluminium window and door systems used for retail purposes.
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Task 1: Identify and describe the appropriate legislation and the context in which the legislation operates.
What is Building Regulation?
According to Borough of Poole (2015) Building Regulations are;
'Minimum standards for design, construction and alterations to virtually every building. They are developed by the Government and approved by Parliament.'
The Building Regulations consist of parts A through to P, these regulations are set standards at national level. The relevant national standard for Northern Ireland is Building Regulations (Northern Ireland) 2012.
Why is Building Regulation Important?
The Building Regulations were predominantly constructed in order to secure an expected standard of; health, safety & welfare, performance and conservation of fuel and power. But it also provides an element of convenience for people. The British Standards and technical approvals are guidance documents which are relevant, as they relate to achieving the specific purposes of the Building Regulations (Northern Ireland) 2012.
Technical Booklets
The Department of Finance and Personnel has created a series of practical guidance booklets with the aim of proving guidance in respect to the technical requirements stated within the Building Regulations (Northern Ireland) 2012.
Guidance in the form of performance standards and design provisions are stated within the Technical Booklets, with the purpose of meeting compliance in accordance with the Building Regulations. An assumption of compliance with the Building Regulations is made if the Technical Booklet guidance is followed, but does not always guarantee compliance. In prospect of achieving compliance with Building Regulations there are alternative methods other than the guidance stated within the Technical Booklets, so there is no requirement to follow any specific provision given in a Technical Booklet.
Technical Booklet F
Technical Booklet F is split up into 2 guidance documents, F1 and F2. F1 is for conservation of fuel and power in dwellings, whilst F2 is for buildings other than dwellings. In relation to the baseline of this report, the guidance located within Technical Booklet F2 relates only to the following requirements of regulations;
39 Conservation Measures
40 Target Carbon Dioxide Emission Rate
41 Consequential improvements
42 Change of energy status
43 Renovation of thermal elements
47 Provision of information
Any building work stated within Technical Booklet F which subjects change to the Part A of the Building Regulations should be carried out in accordance with regulation 23. Technical Booklet B provides guidance measures to achieve these requirements for materials and workmanship.
Technical Booklet F2 guidance does not include procedures which may be required to achieve the requirements of additional legislation, just relates of the requirements of the Building Regulations. Such the legislation may be The Workplace Health, Safety and Welfare Regulations Northern Ireland 1993 & The Energy Performance of Buildings Directive. These pieces of legislation may function during the design/construction periods of a project and can work outside of the limitations of the Building Regulations.
Articles 3 to 6 of Directive 2002/91/EC of the European Parliament and of the Council of 16 December 2002 on the energy performance of buildings is implemented by Part F of the Building Regulations.
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Task 2: Discuss the general considerations and procedures for compliance with the regulations in the context of a proposed extension of 350m2 (floor space) to an existing retail premises with an existing floor space of 1200m2.
In order to achieve compliance with the regulations, Part F2 of the Building Regulations (Northern Ireland) 2012 should be implemented for this non-domestic extension (regulations 39, 40,41,42,43 & 47 apply). Located within paragraph 3.12 of the guidance document is the extensions section. Within this section of the Building Regulations (Northern Ireland) 2012 states the following,
'Where a proposed extension has a total useful floor area that is both '
(a) Greater than 100 m2; and
(b) Greater than 25% of the total useful floor area of the existing building.'
The proposed extension is 350m2 and the existing building floor area is 1200m2, both exceeds what is stated within paragraph 3.12. As it stands, in order to comply with regulation the extension needs to be managed as a new building and should be constructed in accordance with Section 2. The requirement for consequential improvements is applicable for this building, this is discussed in detail in Task 3.
Section 2
Section 2 of Technical Booklet F2 provides an overview of the methodology and limiting values on how Target carbon dioxide Emission Rate (TER) and Building carbon dioxide Emission Rate (BER) is calculated for a new build. BER for the building as built should not exceed the TER after completion, the software calculates this, and covers that aspect of it. But it is also required to prove that Criteria 2 to 5 in this section are met (Building Regulations (Northern Ireland), 2012). Below show Criteria 2 to 5 in more detail;
Criterion 2 – Minimum Acceptable Standards
U Values;
In order for the building to meet U-values requirements of the regulations, BRE Report BR 443 Conventions for U-value calculations should be used as a reference point.
Fixed Building Service Systems;
System efficiencies – Non-Domestic Building Services Compliance Guide must be implemented so that every fixed building service meets the minimum acceptable efficiency. Efficiency rating tests for the fixed building services should be carried out/and certificated in order to achieve compliance with building regulations.
Controls ' Depending on each area of the building and what is the specific requirements, the fixed building services system(s) should be sectioned into distinct control zones. This should be corresponding to the different solar exposure, or occupancy period or type of use.
Energy Metres ' guidance within CIBSE TM 39 Building energy metering should be followed in order to achieve compliance.
Centralised Switching of Appliances ' to enable energy savings, provisions of centralised switches should be considered.
Criterion 3 – Limiting the Effects of Solar Gains
In paragraph 2.54 of the Building Regulations (Northern Ireland) 2012 it is instructed that BS EN 410 should be used to calculate the appropriate solar energy transmittance for each space within the building to ensure standards are meet.
Criterion 4 – Quality of Construction and Commission
Building Envelope;
Following the guidance, construction of the building envelope should be of an adequate standard. Continuous insulation should cover the envelope of the building and set limits of the actual permeability is not exceeded.
Thermal Bridges;
The methods stated within the BRE Report BR 497 Conventions for calculating linear thermal transmittance and temperature factors should be used to calculate linear thermal transmittances and temperature factors for the building. Also demonstration of the details to achieve the temperature factor should be displayed which meets requirements of BRE Information Paper IP 1/06.
Air Permeability and Pressure Testing;
It states within Technical Booklet F2 of the Building Regulations (Northern Ireland) 2012 compliance is met when;
a) 'the measured air permeability is not greater than 10 m3/(h.m2) at 50 Pa; and
b) the BER, calculated on completion using the measured air permeability, is not greater than the TER.'
Compensation through improvements to subsequent fit-out activities in order to combat where it is impractical to meet the design air permeability. No more than 5 days after the completion of the testing a notice should be sent to the district council by the qualified person who completed the test stating the results.
The person carrying out the work is to send a notice in writing to the district council stating the result of the air pressure test, not more than 5 days after completion of the testing.
In the occurrence that the building fails to meet the provisions stated from point a) and b) of this section, remedial measures should be put in place to meet compliance requirements.
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Commissioning of Fixed Building Services;
In order to achieve compliance the following procedures taken from the Building Regulations (Northern Ireland) should be followed.
a) 'CIBSE Commissioning code M: Commissioning management; and
b) the procedures for leakage testing of ductwork given in the HVCA DW/143 A Practical guide to ductwork leakage testing '
Failure to meet the required standard of ductwork system will result in remedial works, and should be implemented in order to achieve requirements in accordance with DW/143.
The person who owns the building is to receive a 'notice of commissioning' as a requirement, this should not exceed a timescale of 5 days after completion of the commissioning process. Also should be signed by a member of personal who is suitability qualified.
Criterion 5 ''- Operating and Maintenance Instructions
To achieve compliance with this criterion, an operating and instruction package is to be given over no more than 5 days after the completion of the project. Within this package should contain a notice (in writing) to the building owner. Also, operational and maintenance requirements, to enable the occupant to operate and maintain the fixed building services efficiently.
Additionally, district council is to be notified in the form of writing that the above has been archived. CIBSE TM 31 Building log book toolkit should be proved as the log book for the building, also, the data to calculate the TER and BER of the
Task 3: Critically evaluate the implications of the required regulatory approach on the fabric and services of the existing building.
Since the application of an extension is being constructed to an existing building with a floor area exceeding 1000m2, in accordance to paragraph 3.73 of Technical Booklet F2 of Building Regulations (Northern Ireland) 2012, consequential improvements must be made to the general energy efficiency of the existing building.
The principle of consequential improvements is;
The Contract Sum = Principal Works + Consequential Improvements (10% at least)
This has a number of general implications.
Implication No. 1:
The projected costings of the contract works is now a combination of the original contract work cost and additionally the 10% for consequential improvements (at least that %). 10% cannot be just added, the first step is to upgrade areas of the building served by the service, then the 10% improvements can be made. The 10% threshold is not capped and can increase. Any improvement cost is then dictated, leaving improvement costs to exceed, and in some cases double the contract works value.
Implication No. 2:
Additionally, costing of a project now contains Contract Works, additional 10% consequential improvements and improvements to the building. This where lies implication number 2, improvements of a building is unknown and needs recognised.
Implication No. 3:
The costings of the 'Improvements to the Building' needs to be established before the over-all cost of a project concerning fixed building services can be projected. The involvement of calculations, surveys and investigations will have to be implemented to decide the magnitude of the improvements, this adding time on the project schedule and also additional costings.
All of the implications stated must be made aware to the client.
Figure 1.0 shows what measures should be taken to the extent that the total cost of the consequential improvements is not less than 10% of the value of the principal works. Current prices should be used to value the cost of the consequential improvements and a suitably qualified person should confirm this in a report (Building Regulations (Northern Ireland) 2012).
Figure 1.0: Consequential improvement measures.
For this particular building measures 1 to 7 should meet the economic feasibility criterion. Measure 8 & 9 is much more capital extensive and may not be visible to the client, but should be discussed as an option.