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Energy Assessment: He wants an as built SAP calc

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    • CommentAuthortony
    • CommentTimeJul 3rd 2009 edited
     
    My building inspector has asked for an as built SAP calc for my house. He likes it but what I would like to do just for fun is to give him one!

    My only source of heat apart from lighting and incidentals is the sun -- effectively my boiler is solar powered and I make all my hot water from this and the surplus heat is stored underground

    My boiler is almost infinitely efficient ( will be when I get a solar powered pump) as it is the sun

    Anyone fancy a crack at the calcs?

    http://www.tonyshouse.info/
    • CommentAuthordelboy
    • CommentTimeJul 4th 2009 edited
     
    Interesting.

    SAP demands a heating system and assumes you'll use electric rads if you don't install an approved one (which is VERY bad for the SAP rating & CO2 emissions). So you need a pretty broad minded SAP assessor.

    I'm not sure I fully understand what you're saying on your website - you are planning on using 2 boreholes as interseasonal heat storage. What are you going to actually use to store the heat? The earth? Water? How big are the boreholes in volume? Can you elaborate?

    Have you done calcs to prove that this interseasonal store would yield and retain enough KWh to meet the winter demands? I see from the graphs that the heating demand is very low (<2,000KWh) and that solar available is 3 times that (5,800KWh), but firstly where is the hot water demand (included in the heating demand?) and secondly how much of that solar energy can you guarantee to retain interseasonally? (It's fair to say many standard solar thermal configurations are 60% efficient, but this ain't a normal case. Also I assume that some of your solar energy comes in the form of gains through the window). Also have you calculated internal gains in Mike George's graphs, and if so, what are they called and where?

    What you need is a SAP assessor who would come up with a way of calculating the CO2 emissions per kwh of your system and find the nearest equivalent in the SAP database (probably wood chip, using next year's figures), as SAP only lets you use approved fuel. So it's a slightly dodgy thing for a SAP assessor to do, but it could be worked through with the accrediting body or the BRE.

    Also surely there is a question about whether you could meet all your hot water needs from your system, even in darkest February. Will you need an immersion boost occasionally? If you say no to this, does that mean you'll put your money where your mouth is and not put an immersion in your cylinder at all?

    But, as I say, interesting. Happy to give other SAP advice as the discussion unfolds. Not sure if I'd be up for doing the calcs with the information I presently have though, but if things get clearer, I'll do 'em.
    • CommentAuthorjon
    • CommentTimeJul 4th 2009
     
    Would installing a heating system composed of a nominal system (say a hand held torch) make the SAP calc work?
    •  
      CommentAuthorali.gill
    • CommentTimeJul 4th 2009
     
    alternatively you may be able to offer a calc using sbem - failing that you'll have to look at dynamic simulation modeling
    • CommentAuthordelboy
    • CommentTimeJul 4th 2009
     
    Jon - if you said that a hand held torch was the heating system, that would mean that SAP assumed it was electric heating - not good. Unless it was a wind up torch, in which case you could present a case for biofuel (ie your food), but I reckon that the BRE and accrediting bodies would slap this down!

    Ali - usually building control officers want SAP calcs done because they want to see a compliance notice. SBEM based software would produce L2A compliance notices which wouldn't be right for new build housing (L1A). Also I'm not aware if SBEM would tolerate this system any more than SAP - I just don't know.

    Similarly I don't think that dynamic simulation software could produce bona fide compliance notices either, although I'm not 100% on that - if anyone knows differently, please say so.

    It all really depends on how broadminded Tony's BCO is - he may have to tick his box and can only do that with a compliance notice, or he may be able to be a little more flexible.

    Personally while I'm open to persuasion, I'm not completely sure how Tony is going to ensure he doesn't have to resort to electric heaters when it's really freezing in February. I'm not saying it's impossible, I'd just like to see how Tony can be so sure he'll not need this.

    And if he does require some electric heating, then this should be reflected in the energy analysis of his house. SAP, however, is too blunt to achieve this fairly, and would treat him unduely harshly, I reckon.
    •  
      CommentAuthorali.gill
    • CommentTimeJul 4th 2009
     
    i'm also not sure on the tolerances of these calc methods but i know sbem was recommended for use on dwellings over a certain size and with features that couldnt be accommodated by the earlier version of sap before the recent update/upgrade.
    I'm hoping to do the training in this http://www.iesve.com/ComplianceUK/Software/VE-SBEM
    and this http://www.iesve.com/ComplianceUK/Software/iSAP
    soon so might be a bit more use with these matters
  7.  
    Posted By: delboySimilarly I don't think that dynamic simulation software could produce bona fide compliance notices either, although I'm not 100% on that - if anyone knows differently, please say so.


    Not bona fide compliance notices, but I have had a Tas simulation accepted in place of the notice. [There is always the flexibility to demonstate compliance by 'another means' within bregs] I argued that since Tas was acceptable for compliance with Part L2 then it must be accurate enough for Part L1. This was accepted by the BCO.
    • CommentAuthortony
    • CommentTimeJul 4th 2009
     
    nice one --- thanks Mike
    • CommentAuthordelboy
    • CommentTimeJul 4th 2009
     
    Tony any info on what the boreholes consist of and how they will store the heat interseasonally?
  10.  
    Should have also said that this was in relation to Part L1b and more specifically a significantly glazed extension plus existing fabric upgrade.

    I suspect Tony's BCO will still want a SAP rating as it is new build
  11.  
    if the house is practically passive... give him the phpp calcs instead...

    if the SAP is much like our BER system.... it is not set up to be favourable to passive or even low energy dwellings..
    • CommentAuthortony
    • CommentTimeJul 4th 2009
     
    delboy -- my boreholes extend 6.5 m below the centre of each half of the basement floor, they are simply plastic pipes surrounded in concrete.

    I pump excess solar heat down there with the intention if speeding up the natural warming of the ground under a building (to the average temp above)

    and then forcing more heat down there to establish a pipe dream temp of 20 C for the ground, my house will then be sitting on its own warm rock.

    I have no ground water even at 9.5m and I am an optimist.
    • CommentAuthortony
    • CommentTimeJul 4th 2009
     
    sydthebeat -- is phpp for free -- I dont do paid for things
    •  
      CommentAuthorali.gill
    • CommentTimeJul 4th 2009 edited
     
    • CommentAuthorMike George
    • CommentTimeJul 4th 2009 edited
     
    I had thought that the SAP software had to be used for new build. Reading Page 11 of Part L1A [CO2 emission rate] this doesn't seem to be the case http://www.planningportal.gov.uk/uploads/br/BR_PDF_ADL1A_2006.pdf

    My reading of it is that you can use any software which will give the required output [ie Notional v Actual] Unless I'm missing something?
    •  
      CommentAuthorali.gill
    • CommentTimeJul 4th 2009
     
    if its a property for sale then an on construction epc is required produced by an ocdea using sap
    http://www.dea-epc.co.uk/constructionEPC.html

    this sheds some light on it - but doesnt clarify
    http://www.homeinspectorsuk.co.uk/sap-energy-assessors.htm
    this is where you find them
    http://www.greenbooklive.com/search/search.jsp?sectionid=10075&partid=10017
    but..
    my interpretation is that this building requires a level 4 or 5 epc to accurately model its heating system and fabric performance therefore a dsm is required via tas or iesve, unless sbem can can accommodate it.
    Therefore although its not a commercial building you'll need a commercial energy assessor as they are licensed to provide a Co2 compliance certificate for non-standard buildings.
    http://www.cibsecertification.co.uk/clients/energy-performance-certificates
    http://www.cibsecertification.co.uk/clients/how-to-get-an-energy-certificate
    • CommentAuthortony
    • CommentTimeJul 5th 2009
     
    I will live in the house myself and am calling it level 6+ or passive house pluss

    from you comment above ali it sounds like my TAS model will do the job as the insulation is as built and I an expecting better air tightness than modeled.

    thanks for the help guys
    •  
      CommentAuthorali.gill
    • CommentTimeJul 5th 2009
     
    only problem you might find tony, is if they request a formal on completion epc which will need to be produced by a licensed assessor - leads back to the thermal modeling software thread and mike george's indecision over whether to pay for the course, the annual fees and the software license to become a level 5 assessor after the debacle of the residential epc scheme. that thread was active a year ago and this is probably the first time the need for a level 5 epc has come up on the forum since then.
    just to clarify rdsap, sap and sbem are a compliance testing methodology.
    dynamic simulation modeling is performance design software that has been tweaked to enable compliance testing.
    http://www.edsl.myzen.co.uk/downloads/misc/EDSL_Newsletter_April2009.pdf
    • CommentAuthorMike George
    • CommentTimeJul 5th 2009 edited
     
    Agree with that ali. As you say, in order to produce the pukka Certificate you have pay megaucks to call yourself a level 5 assessor. Glad I didn't. A freind of mine is qualified to do Level 3 and 4. In his experience there is very little demand for Level 5.

    But this is for an EPC - which is not necessary for a new build unless it is being sold or let. I think it will be down to the interpretation of the BCO whether or not to accept a Tas simulation quantifying predicted and as built CO2
    •  
      CommentAuthorali.gill
    • CommentTimeJul 5th 2009
     
    The Assest Skills presentation on this link simply says on-construction epc is required on completion.
    http://www.assetskills.org/PropertyAndPlanning/EnergyAssessment/OtherInformationEnergyAssessment.asp
  21.  
    Can't find it. Can you give me a pointer to which link on that page please ali
    •  
      CommentAuthorali.gill
    • CommentTimeJul 5th 2009
     
    sorry mike its the one under the text
    'Energy Assessors and their role'
  23.  
    <blockquote><cite>Posted By: ali.gill</cite>says on-construction epc is required on completion.</blockquote>

    Still can't see where it says that. Do you mean slide 7? I interpret it as meaning a DEA can provide and EPC on completion, NOT that an EPC is required under Building regs

    This link http://www.energychoices.co.uk/do-i-need-an-energy-performance-certificate-ask-our-expert.html suggests

    * Sellers or buyers of homes - All sellers of homes need to ensure that they provide a Home Information Pack, which includes an EPC for potential buyers.
    * Builders - An EPC needs to be provided to buyers of newly built properties.
    * Landlords - If you are a landlord, you’ll need to make an EPC available to prospective tenants the first time you let a home after 1 October 2008. EPCs are only required for properties which are self-contained; so if you’re renting a room to a single tenant sharing facilities, it is not necessary.
    * Tenants - If you are looking at renting an entire property then the landlord must make an EPC available to you free of charge.

    Tony doesn't fall into any of the above and I canno find a stated requirement in Part L. Maybe a loophole?
    • CommentAuthortony
    • CommentTimeJul 6th 2009
     
    :swingin:
    • CommentAuthorMike George
    • CommentTimeJul 6th 2009 edited
     
    ... Still need the predicted and as buillt CO2 though [just not an official EPC]

    Which still means SAP, ISBEM or Dynamic Simulation. [depending on what your BCO will accept]
    •  
      CommentAuthorali.gill
    • CommentTimeJul 6th 2009
     
    No i cant find anything that clarifies this in respect to self builds.
    what i do know is that provision of the Co2 calcs is a specialist role similar to having the electrics or gas certified.
    but again it will depend on the individual bco to decide what he is satisfied to accept.
    the part l text seems pretty ambiguous to me.
    -
    question is whether it means on completion of any newbuild project (inc. self-build)- or on completion prior to marketing the property.
    •  
      CommentAuthorali.gill
    • CommentTimeJul 6th 2009
     
    on your link mike it says
    "whenever a building is built, sold or rented out"
  28.  
    <blockquote><cite>Posted By: ali.gill</cite>question is whether it means on completion of any newbuild project (inc. self-build)- or on completion prior to marketing the property.</blockquote>

    The latter I think, but only my opinion. As you say it's all very ambiguous, even my/your quote can be interpreted in more than one way
    •  
      CommentAuthorali.gill
    • CommentTimeJul 6th 2009
     
    the reason i'm swaying towards it being all buildings is because of the database they want to build up of uk properties - i cant imagine they'd let self build slip through the net
  30.  
    Yes but even if they do slip through the net they are just the same as much of the existing stock which is yet to come up for sale. In fact they are guaranteed to be up to a certain standard due to the as built CO2 requirent

    Also it wouldn't be the first time they have left such loopholes in legislation

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