1. Building design

1.1. 3D Building views

Here are the realistic images of my building design from different views.

Here is the design that I did an energy analysis on

1.2 Building envelope characteristics

1.2.1. Walls

For the exterior walls, I used Brick on CMU with a ~32 R value. This goes in hand with my initial decision to stick to materials that can be found locally and can be more sustainable. CMU is already widespread in Kenya - even though it is not the most sustainable material. I thought using Brick which is usually primarily fired earth, would be a good offset to the core CMU. This also goes with my overall ‘earth’ aesthetic.

1.2.2. Roof

I modelled a green roof for my building to go hand in a hand with my sustainability goal of increasing the green spaces in this building. I also read that a green roof could actually makes solar panels functionality better. The main layers of the roof are Grass, gravel for drainage, vapor membrane, metal deck and concrete structural base. The R value is 3.3 which is very low and needs a revisit. Could be because of errors when modelling the roof details

1.2.3. Floor

For level 1, I used steel bar joist with concrete on metal deck (82 R value - needs re designing) for structural support. For the 2 remaining levels, i used light weight concrete on metal deck (R value of ~2.5 - too small?). The finishing in the accommodation rooms will vary from the finishing in the hallways and exhibition spaces, but for now, i just used a blanked concrete floor. I considered using wood flooring but, wood is usually expensive in Kenya and the weather conditions, among other things, aren’t always favorable.

For exterior doors, I used a double store front door for the curtain wall sections and a double exterior double two lite for the non curtain wall sections with exterior doors

I used a simple single fixed doors for interior doors - which could vary for the different rooms, in the future iterations of my design.

I used large windows for the offices, conference room and the accommodation units to maximize views. I also used Trp LoE for the windows based on optimization results from insight that showed that this would have a significant impact on the total EUI. I however will in future make changes such that windows that face directions that don’t get a lot of direct solar heat, could have less glazing.

The mechanical rooms have small fixed windows - I took advantage of the fact that these rooms don’t need to have much in terms of views and using smaller windows could potentially reduce direct heat gain into the building.

1.2.4 Shading/ Sun control features

Overall, the south view has the most openings(windows and curtain walls) for views which might have negative impacts in terms of heat gain, but with the right measures such as the right glazing and shading this can be offset. I will be adding vertical and horizontal shading to these curtain walls in the future but for now, the large overhang is providing a good amount of shading.

The west and the east elevations of my building don’t have as much windows as the north and the south and for the larger windows in these views, I will be adding shading to counter direct solar heat gain.

2. Building Energy Model

Baseline energy model EUI

The baseline model without making any improvements had an EUI of 70.6 kBtu/sf/yr. This was a little higher than ASHRAE recommended value so I started looking for ways to optimize.

After making all adjustments on the insight model to match the characteristics I had on my BIM model, the EUI went down to 69.1 EUI as shown below.

After adjusting building envelope values in Revit to reflect the recommendations from insight, the EUI went down to 53.9 kBtu/sf/yr

Setting the operating schedule to use the BIM value and optimizing lighting efficiency, plug load efficiency values and including daylight controls, lowered the EUI further to 28.9 kBtu/sf/yr which brings me closer to net zero but not close enough.

As predicted by the climate consultant results, plug load and lighting efficiency had a greater impact in lowering the EUI (affect internal load gains)

EUI after lighting efficienc was changed to 0.3W/sf, as well as shading

EUI after changing plug load efficiency to 0.6W/sf

Further exloring effects of installing PV, the EUI went down to 28.9kBtu/sf/yr which is much lower than ASHRAE value of 65.7. This is the final insight results for now

Below is results from a solar analysis that I did ont he latest versiono of the design and compared it to the old very basic mass that i did on module 4.

A solar analysis if the building reveals that the solar pv potential of the building is 582 ,673 kWh/yr which is close to the approximation from the design check in from module 4, as shown below

Module 4 result

Conclusion

Here are key factors that are driving these results:

• Lighting efficiency of 0.3W/sf
• plug load efficiency of 0.6W/sf
• Solar panel efficiency of 16%
• Surface coverage of 90%

Key areas of improvement:

• I will add more shading to the building esp on the south view.
• I am looking to explore ways of including more local materials and more sustainable materials. So far i have brick, but for shading for example, I’d like to use bamboo. For my interior partitions, which are still the generic type currently, there is opportunity to use more bamboo and other sustainable materials
• I am going too focus on reducing operational energy use by implementing controls and paying attention to plug load and lighting efficiency.