Construction, Nonprofits, and Sustainability

Cracking the energy code

March 31, 2018
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All projects in Michigan submitted for permit after Sept. 20, 2017 will have to meet updated energy code standards.

The renewed standard for Michigan is ASHRAE 90.1 - 2013, which was updated from the 2007 version.  The new code mandates a 23.8-percent energy-efficiency increase in building performance, an improvement that should be pleasing to building owners.

However, it does come at a premium that is becoming apparent in the current construction market. On March 13 of this year, numerous trade contractors, engineers, building owners and general contractors attended an informative presentation called “Understanding New Energy Code” by E3M Solutions. The E3M Solutions team did a great job breaking down a highly complicated subject into an organized delivery of how these updates are affecting the Michigan construction industry and what contractors need to be aware of on upcoming projects. 

Major highlights

In Michigan, there are amendments to the ASHRAE 90.1 within the adopted standards. These amendments cover items such as receptacle controls, electrical monitoring, envelope alternates, vestibules, DDC systems and lighting alternatives. For residential projects, reference the MI Residential Code. Projects with R1 building type are subject to the commercial code, as well as all mixed-use buildings. Within the commercial code, there are mandatory project requirements outlined specifically for new construction, additions and renovations. For the building envelope, all buildings must comply.  Building additions must comply, but existing portions are grandfathered under the previous standard. However, there are exceptions to the rules. Review the standard for specifics. Here are a few examples of additional requirements and the cost implications associated:

1. Insulation values have changed, and we are noticing increased costs in many of our new buildings. Per the new code, buildings need to have a continuous air barrier, sealed seams and be fully tested. Testing is hard to do, and there are very few companies that provide this service.  The insulation system also requires inspection prior to being covered.  

2. Building entrances that serve the public or staff must have a vestibule. There cannot be less than seven feet between the doors, and the space cannot be greater than 50 square feet or 2 percent of the gross floor area. There are some exceptions, such as doors not intended for the public, doors directly from dwelling unit, buildings with less than 3,000 square feet and revolving or overhead doors.

3. Skylights are required for buildings over 15 feet tall and more than 2,500 square feet. The minimum amount of skylights required is 3 percent of the space. Exceptions include climate zones 6-8, shading of permanent objects (buildings or other objects blocking daylight) and side lighting tradeoffs. It is important to note that the height of exterior windows may set the requirements for skylights and the amount of lighting controls for daylighting.

Mechanical and electrical systems

Some of the biggest impacts are within the mechanical and electrical scopes of work. For mechanical systems new buildings must comply. Additions to existing buildings shall comply, with the exception of the addition being served by the existing HVAC system. Alterations to buildings shall comply. Exceptions for alterations to a building include equipment being modified or repaired and not replaced, like-for-like replacement that would otherwise require extensive renovation, refrigerant change, relocation of existing equipment and duct or piping where there is insufficient space. Major changes to highlight for mechanical systems are the efficiency improvements to most all of the systems, boiler turn-down ratio, DDC controls, DDC controls commissioning and heating in vestibules.

Electrical systems had many changes in the updated standard as well. Just like the mechanical system, all new buildings must comply. Different from mechanical systems, additions to existing buildings also must comply. Alterations to existing buildings shall comply with some exceptions. Most all of the lighting power density limits were lowered on average 10-15 percent. One of the most notable cost increases is for lighting. Lighting controls are to be manual with secondary shutoff requirement. Occupancy sensor on is no longer sufficient, it needs to be manually on or auto on to 50 percent, and then manually increase to 100 percent. Daylighting controls required in all areas 150 W or greater in primary daylighting zones. Exterior lighting reduction by at least 30 percent from midnight to 6 a.m. or during off-business hours. Lighting controls need to be functionally tested by a certified individual not involved in the design or construction of the system. 

Impact on operational and construction costs

The new buildings, additions and renovations will provide great spaces offering more energy efficiency and building monitoring. New construction projects over 25,000 square feet, tenant spaces over 10,00 square feet and buildings with energy supplied by a utility or plant not within the building will need whole building energy monitoring. These buildings will require record keeping to be stored for at least three years. The 23.8-percent increase in energy efficiency is averaging an operational cost savings of $0.16 per square foot for buildings in Michigan. Nationally, the average operational cost savings is closer to $0.40 per square foot. While the functionality of the standard updates are beneficial to energy consumption, the construction cost for this has been a little unexpected and hard to predict. The construction costs for the increased efficiencies have been reported in the range of $1-$1.25 per square foot. During the presentation with E3M Solutions, it was noted that this figure might be light and perhaps closer to $2 per square foot. Based on the type of building and how the new standard affects the multiple design components of that project, the additional cost could be as much as $5 per square foot. 

Safety is the one item that will always have the highest jurisdiction over the new energy code standard. If requirements to meet the new standard make conditions less safe, there will most likely be an exception. The Authority Having Jurisdiction, or AHJ, building code officials will have the final determination on what is acceptable. When preparing for construction, review any unclear items within your design early on with the AHJ and lean on design professionals like E3M Solutions to provide guidance and interpretation of the updated code standards. For projects outside of Michigan, be aware that ASHRAE 90.1 – 2016 is now out and may apply, but it has not yet been adopted by the State of Michigan. Testing is required on almost all projects, big and small, and no matter what scopes of work are being completed. Have a plan for required testing on all of the different components throughout your building.  

As you design, build, manage and walk-through these new buildings, the newly implemented updates and standards will be recognizable. When in the space, you may notice the lights dimming when the sun starts shining or look up and see the clouds through the skylight above.

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