When & How to Test

When to Hire an Outside Consultant

Many indoor air quality problems are simple to resolve when facility staff has been educated about the investigation process. In other cases however, a time comes when outside assistance is needed. Professional help might be necessary or desirable in the following situations:

  • Mistakes or delays could have serious consequences
  • Building management feels that an independent investigation would be better received than an in-house investigation
  • Mitigation efforts by facility staff have not relieved the indoor air quality problem
  • Preliminary findings by staff suggest the need for measurements that require specialized equipment and training

You may be able to find help by looking in the yellow pages of your telephone book. Local or state health or air pollution agencies may have lists of firms offering indoor air quality consulting services in your area. It may also be useful to seek out referrals from other building management firms.

Note that even certified professionals from disciplines closely related to indoor air quality issues (such as industrial hygienists, ventilation engineers, and toxicologists) may not have the specific expertise needed to investigate and resolve indoor air problems. Individuals or groups that offer services in the evolving indoor air quality field should be questioned closely about their related experience and their proposed approach to your problem.

As with any hiring process, the better you know your own needs, the easier it will be to select a firm or individual to service those needs.

Selection Criteria

Most of the criteria used in selecting a professional to provide indoor air quality services are similar to those used for other professionals.


Ask how much indoor air quality work and what type of IAQ work each firm has done. Have the firm identify the personnel who would be responsible for your case, their specific indoor air quality experience, and related qualifications.

Quality of Interview and Proposal

Competent professionals will ask questions about your situation to see whether they feel they can offer services that will assist you. Their staff should also have a good understanding of the relationship between indoor air quality and the building structure, mechanical systems, and human activities.

The proposal for the investigation should emphasize observations rather than measurements since there is much information that can be gathered prior to any actual testing. Refer to the web page on IAQ Basics for more information on this.


There are no Federal regulations covering professional services in the general field of indoor air quality. For this reason, firms should be asked to provide references from clients who have received comparable services. In exploring references, it is useful to ask about long-term follow-up. After the contract was completed, did the contractor remain in contact with the client to ensure that problems did not recur?

Knowledge of Local Codes

Familiarity with State and local regulations and codes helps to avoid problems during mitigation. Heating, cooling, and humidity control needs are different in different geographic regions, and can affect the selection of an appropriate mitigation approach.


If projected costs jump suddenly during the indoor air quality investigation process, the consultants should be able to justify that added cost. The budget can be influenced by a number of factors, including:

  • complexity of the problem;
  • size and complexity of the building and it’s HVAC system;
  • quality and extent of recordkeeping by building staff and management;
  • type of report or other product required;
  • number of meetings required;
  • air sampling (use of instruments, laboratory analysis) if required

These issues should be covered in advance through the proposal provided and the scope of work contained therein. Experienced indoor air quality investigators should also be able to identify the potential for these cost increases to occur in most cases.

If you would like further information about hiring professional assistance to address indoor air quality problems, click here.