See all forum discussions about NC-2009 EAp2
 Subscribe to new posts about NC-2009 EAp2 Post a new question aboutNC-2009 EAp2
See LEEDuser’s guidance on NC-2009 EAp2»
FAQs about EAp2 :

Our project has a large process load—75%. Despite our efforts to make an efficient HVAC design, the cost savings are minimal. What can we do to earn this prerequisite and be eligible for LEED certification? Is there any flexibility in how we model the p

Can SHGC be higher in the proposed than in the baseline model?

Our process load is higher than 25%. Do we have to justify that?

Do I need to justify the electrical and fuel rates I am using in my model?

Our local code references ASHRAE 90.1-2010. Should I use that for my documentation, or 90.1-2007?

Can I claim exterior lighting savings for canopy lighting even though a baseline model cannot include shading elements?

The project is built on a site with existing exterior lighting installed. How should this be accounted for?

Can mezzanines open to floors below be excluded from the energy model?

How do I provide a zip code for an international location?

For a project outside the U.S., how do I determine the climate zone?

For a project outside the U.S., how do I determine the Target Finder score?

Do hotel rooms need automatic light shut-off control?

How commonly are the 90.1 mandatory compliance forms submitted as part of EAp2/EAc1?

The Section 9 space-by-space method does not include residential space types. What should I use?

Can the Passive House Planning Package (PHPP) be used to energy model for LEED?

Is it acceptable to model a split-type AC with inverter technology compressor as a heat pump, like modeling VRF?

Can the Trace 700 'LEED Energy Performance Summary Report' by uploaded to LEED Online in lieu of the Section 1.4 tables spreadsheet?

A portion of our building envelope is historic. Can we exclude it from our model?

Which baseline HVAC system do I use if my building has no heating or air conditioning?

For an existing building, do I need to rotate the model?

View answers »

Forum discussion

NC-2009 EAp2:Minimum Energy Performance

Existing envelope

Default Avatar
Sandra Holmström
environmental consultant
Bengt Dahlgren AB
LEEDuser Basic Member
1 thumbs up

We have a project that is a major renovation of an existing building. We are planning on using the Existing envelope pathway - and thereby keeping the existing envelope in both the Proposed and Baseline building, which also allows us to take credit for improvements of the envelope in the Proposed building. How is this handled for parts that are new construction? The building is expanded with 3 more floors on the existing top floor. Is it possible to comibine existing and new construction so that in the Baseline we use ASHRAE 90.1-values for the new construction and existing envelope for the lower floors? Also, since the baseline building shouldn´t be rotated for an existing building - is this ignored for the top floors as well (new construction)? Thanks in advance, Regards,

0
Post a reply

You rely on LEEDuser. Can we rely on you?

LEEDuser is supported by our premium members, not by advertisers.

Go premium for $15.95  »

Profile picture for user sheffer
Marcus Sheffer
LEED Fellow
7group / Energy Opportunities
LEEDuser Expert
4454 thumbs up

Wed, 05/13/2015 - 13:23

The new construction uses the Table 5.X values for the Baseline. The lower portions which were existing can use the previous condition. So yes you combine the methods. As long as the addition is less than 50% of the total you do not need to rotate the baseline.
Profile picture for user neerajsh.2807
Neeraj Sharma
Sustainability Manager
Conserve Solutions- Riyadh, Kingdom of Saudi Arabia
LEEDuser Basic Member
1 thumbs up

Tue, 02/04/2025 - 09:50

Mr. Marcus,  I'm using the existing envelope values for my baseline case, but I'm unsure about the Window-to-Wall Ratio (WWR) for the floors. Should I maintain the existing 98% WWR or reduce it to 40% while keeping the envelope values the same?
Profile picture for user sheffer
Marcus Sheffer
LEED Fellow
7group / Energy Opportunities
LEEDuser Expert
4454 thumbs up

Tue, 02/04/2025 - 15:23

Which version of LEED/ASHRAE 90.1 are you using? This forum is for an older version of LEED that has sunset.

Add new comment

To post a comment, you need to register for a LEEDuser Basic membership (free) or login to your existing profile.