Ammended national building regulations for energy use

by Darren
natbusreg jnl5


The amendments to the National Building Regulations for Energy Usage in Buildings have been implemented and SANS 10400XA Energy Usage in Building established to meet these requirements. In this document the modus operandi of the new Regulatory Environment is outlined.

The amendments to the National Building Regulations and the publication of SANS10400XA as above has placed the Built Environment Professional, and particularly the Architects in a pivotal position to influence the implementation of Energy Efficiency and Sustainability in building. This is along-side the Building Control Officers in the Local Authorities. The system places a heavy reliance on the integrity of the Professions in assuring the compliance of and sustainability of buildings.
It is essential that all parties understand their role in the process for it to function as is intended, and this article sets out to clarify the roles of the Parties.

The amended Regulations for Energy Usage, some interpretations and date of implementation
As per Notice R711, in the Government Gazette of 9 September 2011, the amendments to the National Building Regulations, are made in terms of the National Building Regulations and Standards Act 103 of 1977 and require (in summary):
XA1:    That buildings use energy efficiently and reduce Greenhouse Gas emissions in accordance with requirements detailed.
XA2:     That not more than 50% of the annual volumetric requirement of domestic hot water may be supplied by means of electrical     resistance heating.
XA3:    Provides for three methods by which compliance with the functional Regulation (XA1) is demonstrated. These three methods or routes are also set out in paragraph 4.2.1 of SANS10400XA, and by following one of these compliance routes the requirements of Part XA of the National Building Regulations will be met.
The Regulations, as published, were legally effective from 10 November 2011, and the RSA Government is bound to promote and defend their implementation, via the mechanisms and procedures established to control new buildings.  This is a function devolved to Local Authorities and specifically Building Control Officers.
In this regard the Regulator has assisted with the development of foundation training material, and has embarked upon a programme to train Building Control Officers in the implementation of the Regulations. This material has been used to train many Building Professionals and has been used as a basis for other courses. Inevitably the wording of the law (Regulation and Standard) has different interpretations and this has led to some variations as to how the Regulations are applied. The views expressed in this document have been tested with the drafting team and can be regarded as a generally accepted interpretation.

SANS 10400XA satisfies the Regulations
The Regulation XA3 sets out that SANS10400 Part XA; Energy Usage in Buildings, is “Deemed-to-Satisfy” the Regulations. This document is therefore the logical starting point for those persons who need to demonstrate compliance with the Regulations, and this will apply to most projects except the Factories and Warehouse portion of a building.
Regulation XA3 and SANS10400XA sets out three routes to compliance with SANS 10400XA, namely;
(i)    Prescriptive provisions for the building envelope and services per XA3(a)
(ii)    A Reference Building route per XA3(b)
(iii)    The Energy Usage and Demand performance  requirement method per XA3(c)

The three methods of compliance are all ‘Deemed-to-Satisfy the Regulations’, however, not all routes are generally available to all persons. A distinction is made between the projects for which compliance is demonstrated by way of a Rational Design by a “Competent Person – Energy” and projects for which the Building Envelope and Services route is followed. This latter route is available to all persons.   

Prescriptive route or the Building Envelope and Services route
Regulation XA3 (a) provides that route (i) (the Building Envelope and Services route) is generally available to the Appointed Person or his/her nominee, and is the person who may be responsible for the design of a building and compliance with the Regulations.  
This route requires the detailed observance of all relevant provisions of SANS10400XA and SANS204, where specifically invoked, as per the key clause of 4.2.1 b). This section refers to other sections in SANS 10400XA and in some instances particular clauses in SANS 204. For example the calculation methods of paragraph 4.3.4 of SANS 204 for fenestration are invoked when the window are is greater than 15% of the net floor area.
This compliance route is available to the owner (Responsible Person) or the professional team (Appointed Persons) for the demonstration of compliance without having to convince a client or the Building Control Officer of his or her competency.

It is not necessary for a Competent person to perform this function, or to perform the fenestration calculations.

Rational Design options
Two of the compliance routes established in Regulation XA3 and in SANS10400XA, provide that a Rational Design may be performed in compliance of the Regulations by the Competent Person.
The definition of a Rational Design is provided in SANS10400 Part A and is the application of a process of reasoning and calculation, possibly based on a widely accepted standard or document.  In the wider sense (the) document may be a computer programme, such as reputable energy modelling software, which are usually based on standards such as ANSI/ASHRAE Standard 140-2007.
The Rational Design in terms of SANS10400XA can only be performed by the ‘Competent Person (Energy) as per paragraph XA3(b).

Acceptance of Competence and the compliance route decision
The Regulations require the Responsible Person (The building owner) to make a declaration appointing a Professional (as identified by the Council for the Built Environment Act 43 of 2000), as the Appointed Person. This will in most cases be the Architect, and this person is required to make a Declaration as to the means by which the regulations will be satisfied, and to provide the names of the Competent Persons (if one is required) who will assist the Appointed Person, on the requisite Form 1.
If no competent Person is required then the Appointed Person will be obliged to follow the Prescriptive Route, and indicate this election the last section of Schedule A to Form 1, which will accompany the application for planning approval.
The acceptance of responsibility by the Competent Person is set out on Form 2, together with a Declaration by the Competent Person as to the qualifications, experience and contextual knowledge necessary to undertake such work, and the Local Authority’s acceptance of the declarant as an approved Competent Person.
The responsibility assumed by the appointed Competent Person for a portion of the system is acknowledged in Form 3, which also contains critical design Information and a Certificate of Completion. The competent person who is responsible for such determination shall on completion of the construction and commissioning of the building submit to the local authority a fully completed Form 4 as contained in SANS 10400-A.

If there is no Competent Person then the Form 4; Certificate of Completion will need to be signed off by the Appointed Person who will be the Architect in most cases.
The present form does not accommodate the situation that the signatory is not a competent person, but it is suggested that the applicant should endorse the application by deleting the words ‘Approved Competent person’ and inserting after National Building Regulations reference to the fact that SANS 10400XA paragraph 4.2.1 b) has been followed.

Energy Usage and Demand compliance route    
The Energy efficiency performance requirements for the building types in occupancy categories specified (Offices, Shopping Centres and Institutional Buildings) are set out as per Table 2 & 3 of the SANS 10400XA standard.
It will be necessary to perform a calculation or modelling of the theoretical annual energy usage and energy demand, to assess whether the required energy and demand criteria of these tables are met.
The theoretical annual energy consumption of the buildings are calculated using (Agrément South Africa) Certified thermal calculation software, and climatic data as published by Agrément South Africa, to formulate the energy usage forecast.
In order to achieve a uniform basis for assessing building performance, standardised stipulations are required to be made, when using energy design software.  These cover the following areas:

  • Occupancy hours
  • Occupancy density
  • Small power internal heat gains
  • Temperature set points for operation of the building
  • Ventilation assumptions
  • Heat gains for occupants

The Prescriptive or Building Envelope and Services route
All buildings including residential buildings, hospitals and those classes of building which are not built according to a rational design by a ‘Competent Person’ and the performance requirements of Tables 2 & 3, need to be designed & built in accordance with paragraph 4.2.1 b) of the standard.
This section contains requirements for, walls, fenestration & roofs, and floors if in-slab heating is installed, and for hot water (as per the Regulation XA2).
The orientation, shading and building services invoke the provisions of SANS 204: Energy Efficiency in buildings and these are hence deemed-to-satisfy.  
This will require the Architect and / or Engineering Professionals and the Contractors to ensure that the prescriptive requirements of SANS10400XA and relevant parts of SANS204 are met.  
This method of compliance is required to be selected by the Appointed Person at the outset of the project and may be implemented by the Professional Design and the Construction Team without the appointment of a Competent Person – Energy.

The Reference building route
A reference building is initially designed with all of the elements necessary in terms of the above Building Envelope and Components route, and is then compared with the planned design.
The initial building is modelled with the prescriptive aspects built into a base case design in order to establish a reference energy usage and demand budget. SANS10400XA is specific in regard to certain aspects of the buildings shell, but the balance of the detailed requirements for Building Services are to be found in SANS204.
The design is thereafter modified with the required features of the professional team and the annual energy usage and demand is compared to the reference building. If the modified design shows an equivalent or improved energy usage over the reference building it can be said to comply with the regulations.
Some potential for flexibility is built into the standard by the introduction of the so called ‘Reference building method’. This will give opportunity to the Architect or the Engineering professionals or the Contractor to introduce innovative energy efficiency aspects which will yield the same or more energy efficient building than would be achieved by the application of the Building Envelope and Components methods.This (Reference Building) method is exclusively available to the Competent Person – Energy.

The proof of competence
For those (many) more simple building projects, as it can be seen from the above explanation of the working of the regulation and standards, it is not necessary for the Architect submitting plans to be a Competent Person. It should be possible for all professionals to continue handling the type of project they are accustomed to and doing the typical work they are usually doing, and to be able to demonstrate compliance with XA1 – XA3 one way or another.
When following the Prescriptive route of paragraph 4.2.1 b) no Architect/Designer has to prove compliance to anyone other than his/her client. The Building Control office has jurisdiction only over how the detailed requirements of 4.2.1 b) are demonstrated to be complied with.
For more complex projects and those projects and for those individuals who are seeking to act as Competent Person in order to carry out the clients mandate by using either of the two compliance routes requiring a Rational Design, then the Forms 1 – 4 will need to reflect the motivation for the appointment of that person and his or her credentials will need to be presented. In this instance the Building Control Officer will need to be satisfied of the aspirant Competent Person’s education, training, experience and contextual knowledge to make a determination in terms of the Functional Regulation, as per the definition of a Competent person.
As to how the contextual knowledge aspect is proven, clients and Building control Officers might look to the aspirant Competent Persons participation in various courses which are accredited by the SA Institute of Architects (SAIA), and as may be presented by suitably experienced Architects and Engineers or members of the SA Association of Energy Efficiency and its training wing, or those courses run by the SA Institute of Architectural Technologists or those of Structatherm Projects/WSP, who have achieved recognition by the SAIA, Consulting Engineering South Africa and the Green Building Council of South Africa.
No person, Government Official or Institution has sole jurisdiction or authority to accredit any particular persons or group of persons as Competent Persons energy.

Guidance and comments as the choice of compliance routes
The factors influencing the choice of compliance route are:

  • the size of projects
  • and the skills blend in the Professional team
  • client preferences and willingness to pay for energy modelling

Clients will be advised to appoint a professional team with the requisite skills in the energy usage area. Thus the Architect, Quantity Surveyor should all be aware of the need to design for energy efficiency aspects, even if simply to meet the regulations, but also to make the appointment of the Competent Person – Energy, who can add considerable value to the project.
If the Competent Person – Energy is not appointed then the project has only the option of the prescriptive Building Envelope and Services route available to them
If the competent Person has at his or her disposal a team with the requisite energy modelling expertise, then designs can be checked for compliance at an early stage, and a cost effective design can be developed, by way of the Rational Design options available in the regulations.

Thus the three options of compliance route provide a flexibility which will be useful in accommodating small projects (Prescriptive route), larger projects (Performance Route) and a third Rational Design option (Reference Building Route) when the Prescriptive route might appear too onerous.

The author of this document, Howard Harris, has been variously a member of the Research Steering Committees instrumental in providing the fundamental research on which the SANS 204 (its precursor SANS 286) was based, has been a Research Service provider to the (then) department of Minerals and Energy in assessing the viability of the proposed SANS204 performance requirements, has been a Chair of SC61 which is the processor to SABS Technical Committee 59G the committee responsible for producing the SANS 10400XA and 204 standards, and has worked on various of the working groups since 2003/4. He has also been instrumental in bringing SANS 50001 and SANS 50010 to publication via SABS TC242, in the field of Energy Management and Measurement & Verification of energy savings. Howard hold the qualifications of B.Sc.(Chem), C.A.(S.A.) M.Eng.(Mech), C.E.M. , C.M.V.P. He is the Managing Trustee of Structatherm Projects who run training courses for Architects and Engineers in the energy field, and a Director of SP Energy which is involved in energy retrofit projects.Howard is also a former Technical Director of WSP Energy Africa and Managing Director of Structa Industries.

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