Thank you for contacting the UVM Master Gardener Helpline with your question about the raised beds at your place of employment.  I commend your generosity in taking on the project of planting the beds this season. 

One concern that comes to mind is making sure that the beds stay watered on the weekends or other times when you are not working.  When it’s really hot, just a day of too dry soil can stunt or even kill your plants.  When it is really hot and dry, you may need to water multiple times a day.  You will want to be careful to water after weeding which disturbs the roots of the plants (especially seedlings).  If possible, avoid planting/weeding in the hottest part of the day to allow the roots time to adjust to the soil changes. 

I found an article that addresses your concerns about the heat generated by the building.  It was published by the Oregon State University Extension Service and is entitled “Heat wave in the garden:  How to Identify and Prevent Heat Stress in Plants”.  https://extension.oregonstate.edu/catalog/em-9556-heat-wave-garden-how-identify-prevent-heat-stress-plants.  It might be helpful if you have a thermometer to track of temperature in your bed 24 hours a day so you can monitor the temps.

I have a few other article suggestions that might be helpful:

• A booklet entitled “A Guide to Raised Bed Gardening in Miami-Dade County, Florida” published by the University of Florida Extension.  This covers options for watering your beds, as well as mulching which will help retain the moisture in your bed:  https://www.google.com/url?client=internal-element-cse&cx=<personal data hidden><personal data hidden>:rljk-euizvq&q=https://sfyl.ifas.ufl.edu/media/sfylifasufledu/miami-dade/documents/landscapes-amp-gardening/Raised-Bed-Garden-Book.pdf&sa=U&ved=2ahUKEwi_p42Eo_qSAxXCMlkFHbDuMg4QFnoECBAQAQ&usg=AOvVaw36re1-Qku7KdHdzl6ywBqs&fexp=73152292,73152290
• Watering the Vegetable Garden – University of Minnesota Extension:  https://extension.umn.edu/how/watering-vegetable-garden
• An article that will help you diagnose problems with your plants was published by the Oregon State University Extension entitled “Environmental Factors Affecting Plant Growth:  https://extension.oregonstate.edu/gardening/techniques/environmental-factors-affecting-plant-growth

Finally, you might find it helpful to complete a soil test on the bed to ensure that your soil will be compatible with the plants you are trying to grow.  It is possible the crop failure in previous years was related to the health of the soil.  You will want to do the test in the spring when you can access the soil, but don’t wait too long because it takes some time to get the response back from the lab.  This site provides you with information about how to take and submit a soil sample for testing:   https://www.uvm.edu/extension/agricultural-and-environmental-testing-lab

I hope this information is helpful.  If you have any additional questions, please feel free to reach out.  I wish you the best of luck with your raised bed project this summer!